GATE questions, answered.

rospective students who are considering majoring in Chemical Engineering will have to take advanced math courses in addition to the required courses in chemistry and physics. Some of the math courses they will be required to complete include calculus, multivariable calculus, differential equations and linear algebra. Chemical Engineering is a challenging major. In addition to the core courses in chemistry and physics, students will required to complete many advanced math courses. According to the College Board website, www.collegeboard.com, students who are enrolled in a Chemical Engineering program must enjoy solving math problems and be able to collaborate with others while working on a project. Below you will find a short list of Math courses that are required for the completion of a Chemical Engineering degree. Calculus Introductory Calculus is generally taught in three sections over a period of a year and a half.Students enrolled in the first-level calculus class will almost always work with one variable. Some of the areas covered in a single-variable calculus course include: * Polynomials * Derivatives * Logarithmic functions * Limits * Integration * Qualities of the real number system Multivariable Calculus Unlike introductory calculus, which exclusively focuses on a single variable, multivariable calculus focuses on solving problems in calculus that have more than one variable. Some of the topics that a Chemical Engineering student may encounter in this Math course include: * Differentiation involving several variables * Vector-valued functions * Multiple integration * Line integrals * Vector analysis and surface integrals Differential Equations The subject of differential equations is often thought of as a language that expresses the laws of nature. Chemical Engineering students enrolled in a differential equations course will cover: * Linear systems of differential equations * Fourier series applications * Stability * Bifurcations * Numerical methods * Nonlinear systems Linear Algebra Linear algebra and the closely related analytic geometry are used extensively in natural sciences like chemistry. Students enrolled in a linear algebra course learn about solutions to linear equations, linear independence, determinants, eigenvalues, subspaces and matrices and vectors.

Chemical Engineering examines methods to develop, manufacture and utilize chemical and biochemical products. Chemical Engineers research chemical combinations with the goal of finding new uses and products for chemical raw materials. Almost every manufacturing industry employs chemical engineers. Chemical and Biological Processes Chemical Engineering begins with understanding of the basic processes involved in chemical and biological transformations. Such processes are involved in the manufacturing of chemicals, electronics, food processing, pharmaceuticals, biotechnologies and other industries. Chemical Engineering requires an understanding of chemical reaction mechanisms and the laws and principles of thermodynamics, including the thermodynamic properties of mixtures and phase changes. The field requires analysis and the ability to perform chemical extraction, stripping, distillation and absorption. Kinetic and Mechanical Processes Chemical Engineering also requires knowledge of chemical reaction kinetics, including the properties and mechanisms of catalysts and fluid dynamics. The study of fluid mechanics covers macroscopic mass, momentum and energy balances, along with the dimensional analysis of friction and drag coefficients. Chemical Engineers also study polymerization mechanisms, the polymerization process and the mechanical properties and flow behavior of polymers. Chemical Engineering Technology Chemical Engineering can be applied to many different areas of sciences, including sustainability and sustainable development, natural resources and their utilization, industrial ecology, global warming, eco-efficiency and risk assessment. It can also be applied to transport phenomena in living systems, including the lung, microcirculation, the cornea and blood. Biochemical Engineering Within Chemical Engineering, biochemical engineering is also used to understand the behavior and properties of pharmaceuticals, drug delivery systems and other biotechnology products, such as advanced sutures or blood replacement products. The discipline covers the life sciences, microbiology, modern genetics, metabolic stoichiometry, energetics, bioreactors, product recovery and growth kinetics. Chemical Engineering Applications Chemical Engineers can work in a variety of different areas, including producing chemicals, manufacturing chemical-based products, dealing with by-products and supervising production. They may work in industries manufacturing chemical products, such as petrochemicals, agrochemicals, ceramics, fuels, plastics, glass, inks sealants, adhesives, paints, detergents, explosives, oleochemicals, wood processing and environmental technology. They may also work in industries, such as clothing, electronics, food, energy and paper, which utilize suitable chemicals.

s an online graduate, you can start a career in chemical engineering. You'll be responsible for testing new products or developing new chemical compounds used in manufacturing, agriculture and a variety of other industries. The minimum requirement for a career in chemical engineering is a bachelor's degree. The U.S. Bureau of Labor Statistics (BLS) reports that while demand for chemical engineers should decrease by 2% between 2008 and 2018, you'll be able to find employment opportunities in research (www.bls.gov). Many of these research opportunities will be in consulting, pharmaceuticals and biotechnology. In 2009, the BLS reported that median earnings in this profession were $88,280.

As an online student, you'll first assess your academic strengths and weaknesses with the help of an advisor. Your advisor will then help you chart a course of study specific to your career goals, which will be completed through downloadable lectures, video and audio materials. Some online programs offer a set of personalized coursework instead of requiring that all students complete the same classes.

Your study in an online program will begin with the fundamentals of chemical engineering, such as physical and analytical chemistry, engineering mathematics, thermodynamics and industrial mathematics. You'll then learn about polymers, fluid dynamics and how to create different chemical compounds. Mass transfer, separation and the transport process are also covered. Self-study and experiential learning opportunities will teach you how to apply this knowledge as a chemical engineer.

Like all engineers, chemical engineers use math, physics, and economics to solve technical problems. The difference between chemical engineers and other types of engineers is that they apply a knowledge of chemistry in addition to other engineering disciplines. Chemical engineers sometimes are called 'universal engineers' because their scientific and technical mastery is so broad.

Some chemical engineers make designs and invent new processes. Some construct instruments and facilities. Some plan and operate facilities. Chemical engineers have helped develop atomic science, polymers, paper, dyes, drugs, plastics, fertilizers, foods, petrochemicals... pretty much everything. They devise ways to make products from raw materials and ways to convert one material into another useful form. Chemical engineers can make processes more cost effective or more environmentally friendly or more efficient. As you can see, a chemical engineer can find a niche in any scientific or engineering field.

The career options in chemistry are practically endless! However, your employment options depend on how far you have taken your education. A 2-year degree in chemistry won't get you very far. You could work in some labs washing glassware or assist at a school with lab preparation, but you wouldn't have much advancement potential and you could expect a high level of supervision. A college bachelor's degree in chemistry (B.A., B.S.) opens up more opportunities. A 4-year college degree can be used to gain admittance to advanced degree programs (e.g., graduate school, medical school, law school). With the bachelor's degree, you can get a bench job, which would allow you to run equipment and prepare chemicals. A bachelor's degree in chemistry or education (with a lot of chemistry) is necessary to teach at the K-12 level. A master's degree in chemistry, chemical engineering, or other field opens up far more options. A terminal degree, such as a Ph.D. or M.D., leaves the field wide open. In the United States you need at least 18 graduate credit hours to teach at the college level (preferably a Ph.D.). Most scientists who design and supervise their own research programs have terminal degrees. Chemistry is a part of biology and physics, plus, there are lots of categories of chemistry! Here's look at some of the career options related to chemistry:

* Chemical engineers enjoy excellent job opportunities in various industries, from the refining of petroleum products and manufacture of plastics, fertilizers and chemicals, to synthesis of pharmaceuticals, biotechnology, environmental protection, conversion of fossil fuels and other energy related processes. * Chemical engineering is a very attractive major for the student who wants to pursue a careers in medicine, law and business. * Numerous surveys have showed that chemical engineers are one of the highest paid professional amongst engineers.

Computer Engineering combines electrical engineering and computer science to focus on the design and implementation of computer systems (logic devices and software). It is generally part of the engineering department at a university and requires a strong background in math. Computer Engineering Computer Engineering involves the design of computer systems (hardware and software) and related devices. It uses the techniques and principles of electrical engineering and computer science, but also covers areas, such as AI (artificial intelligence), robotics, computer networks, computer architecture and operating system. The electrical engineering aspect of the discipline includes designing application devices, interface hardware, memories, and computer chips. The computer science component involves software engineering, programming, operating systems, algorithms and data structures. A computer engineer's job involves the entire computer system and he or she is comfortable working with both the hardware and software. The results of Computer Engineering can be seen in practically every aspect of life today. Computer engineers work in many areas, including: Embedded Systems An important aspect of Computer Engineering is 'embedded systems' (computer software and hardware designed for a specific device). For example, alarm systems, video recorders and audio players that are digital and cell phones are all a result of Computer Engineering in the area of embedded systems. Most of the software design involves interfacing the device with another device or with a user. Networking Computer Engineering involves building networks, both WAN (wide area networks) and LAN (local area networks). Other areas that a computer engineer may work in include mobile and wireless technology, telephony communications and integrated services. Multimedia This area involves processing of multimedia information. Computer Engineering looks into support for multimedia libraries and databases and retrieval of information. VLSI Systems This area is concerned with very large scale integration - VLSI - systems and circuits and computer security and architecture

Careers in Computer Engineering Technology require some training, usually achieved through an associate's degree or bachelor's degree in Computer Engineering Technology. Though breaking into a career in Computer Engineering Technology may take only two years of collegiate study, be prepared to continue learning new information as technology develops and changes. Read on to discover how you can enter the workforce as a Computer Engineering Technician or Technologist. A Computer Engineering Technician inspects, maintains, builds or sells computers or other technological devices. According to the United States Bureau of Labor Statistics at www.bls.gov, people interested in a career in Computer Engineering Technology should have at least an associate's degree in Computer Engineering Technology. If you have good math skills, love to solve problems and think outside of the box, you have the building blocks for a career in Computer Engineering Technology. Choosing the Right Computer Engineering Technology Degree Program Choosing an Associate's Degree Most people in the Computer Engineering Technology field have an associate's degree. As you look for your ideal program, find out which programs are accredited by ABET, because many employers prefer graduates from an ABET-accredited program. Find out if the degree program is designed to teach you the skills needed to be an entry-level Computer Engineering Technician or if it is used as a stepping stone for further studies. Considering a Bachelor's Degree People with a bachelor's degree in Computer Engineering Technology usually go on to become Computer Engineering Technologists. Technologists generally advance in their organization more quickly, receive more responsibilities, supervise more often and get more difficult assignments. Though there is not a large difference in the entry-level pay rates for technologists and technicians, employers may give preference to graduates with a bachelor's degree during hiring. Training After Employment Education does not stop after college for the Computer Engineering Technician. Once you find a job as a technician or technologist, you will gradually complete more complex assignments with less supervision. You will need to stay current on technological advances. A professional certification is not usually considered necessary, but certification is available through the National Institute for Certification in Engineering Technologies.

If you want to be a Computer Science Major, get ready to program or code. If you want to be a Computer Engineering Major, get ready to design and build hardware. Both allow graduates to work in the field of computers, just in different ways. Computer Science and Computer Engineering have shared similarities. Prospective students in either major will find an overlap of material. Both are concerned with computers, and both examine hardware and software. However, there are differences between the two areas of study. Computer Science Computer Science is a bonified discipline all on its own, originally springing from math departments. It has its basis in mathematics and covers various theories, system organizations, formal languages and logic, in addition to programming languages, software management, bioinformatics and numerical analysis. Computer Science also explores areas, including computer architecture, software systems, operating systems and numerical methods. It may be a better choice for those who want to increase their understanding of data structures and algorithms and who want to code or program. Coursework for this major can include: * Comparative Languages * Numerical Methods * Computer Organization and Architecture * Theory of Computation * Parallel Computation * Data and Algorithm Analysis Computer Engineering Computer Engineering, on the other hand, focuses on the design and development of computers and specialized software. Computer Engineering Majors focus how a computer becomes a physical system. This area covers topics, including electronics and circuits and may be a better choice for students who are interested in building and programming their own computer. Generally, programs in Computer Engineering are associated with electrical engineering or physics departments of a university. Coursework for this major can include: * Basic Circuit Theory * Digital Computer Design * Signal and System Theory * Object Oriented Programming * Electronic and Digital Circuits * Engineering Probability

The Computer Engineering (CE) program at Texas A&M is jointly administered by the CSE and the ECE departments. There are some slight differences in the degree requirements between the two departments. You should select the department by studying faculty web sites and applying to the department with faculty whose interests most closely match yours. You cannot apply to both departments at the same time. Faculty in each department co-advise students in the other department, so if you are admitted to one department and find your closest research match in the other department, you can still work with that faculty member.

Chemistry has a reputation for being a complicated and boring science, but for the most part, that reputation is undeserved. Fireworks and explosions are based on chemistry, so it's definitely not a boring science. If you take classes in chemistry, you'll apply math and logic, which can make studying chemistry a challenge if you are weak in those areas. However, anyone can understand the basics of how things work... and that's the study of chemistry. In a nutshell, the importance of chemistry is that it explains the world around you. Chemistry Explains... * Cooking Chemistry explains how food changes as you cook it, how it rots, how to preserve food, how your body uses the food you eat, and how ingredients interact to make food. * Cleaning Part of the importance of chemistry is it explains how cleaning works. You use chemistry to help decide what cleaner is best for dishes, laundry, yourself, and your home. You use chemistry when you use bleaches and disinfectants and even ordinary soap and water. How do they work? That's chemistry! * Medicine You need to understand basic chemistry so you can understand how vitamins, supplements, and drugs can help or harm you. Part of the importance of chemistry lies in developing and testing new medical treatments and medicines. * Environmental Issues Chemistry is at the heart of environmental issues. What makes one chemical a nutrient and another chemical a pollutant? How can you clean up the environment? What processes can produce the things you need without harming the environment? We're all chemists. We use chemicals every day and perform chemical reactions without thinking much about them. Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything. Importance of Taking Chemistry Everyone can and should understand basic chemistry, but it may be important to take a course in chemistry or even make a career out of it. It's important to understand chemistry if you are studying any of the sciences because all of the sciences involve matter and the interactions between types of matter. Students wanting to become doctors, nurses, physicists, nutritionists, geologists, pharmacists, and (of course) chemists all study chemistry. You might want to make a career of chemistry because chemistry-related jobs are plentiful and high-paying. The importance of chemistry won't be diminished over time, so it will remain a promising career path.

The first known chemist was a woman. A Mesopotamian cuneiform tablet from the second millenium B.C. describes Tapputi, a perfumer and palace overseer who distilled the essences of flowers and other aromatic materials, filtered them, added water and returned them to the still several times until she got just what she wanted. This is also the first known reference to the process of distillation and the first recorded still.

Chemistry is the study of matter and energy and the interactions between them. This is also the definition for physics, by the way. Chemistry and physics are specializations of physical science. Chemistry tends to focus on the properties of substances and the interactions between different types of matter, particularly reactions that involve electrons. Physics tends to focus more on the nuclear part of the atom, as well as the subatomic realm. Really, they are two sides of the same coin.

If you answered "Dmitri Mendeleev" then you might be incorrect. Dmitri Mendeleev presented his periodic table of the elements based on increasing atomic weight on March 6, 1869, in a presentation to the Russian Chemical Society. While Mendeleev's table was the first to gain some acceptance in the scientific community, it was not the first table of its kind. John Newlands had published his Law of Octaves in 1865. The Law of Octaves had two elements in one box and did not allow space for undiscovered elements, so it was criticized and did not gain recognition. A year earlier (1864) Lothar Meyer published a periodic table which described the placement of 28 elements. Meyer's periodic table ordered the elements into groups arranged in order of their atomic weights. His periodic table arranged the elements into 6 families according to their valence, which was the first attempt to classify the elements according to this property. While many people are aware of Meyer's contribution to the understanding of element periodicity and the development of the periodic table, many have not heard of Alexandre-Emile Béguyer de Chancourtois. de Chancourtois was the first scientist to arrange the chemical elements in order of their atomic weights. In 1862 de Chancourtois presented a paper describing his arrangement of the elements to the French Academy of Sciences. The paper was published in the Academy's journal, Comptes Rendus, but without the actual table. The periodic table did appear in another publication, but it was not as widely read as the Academy's journal. de Chancourtois was a geologist and his paper primarily dealt with geological concepts so his periodic table did not gain the attention of the chemists of the day. The modern periodic table orders the elements according to increasing atomic number rather than increasing atomic weight, but the earlier tables were true periodic tables since they grouped the elements according to periodicity of their chemical and physical properties. Protons, which define elements today, were unknown at the time.

A scientist is a person who has scientific training or who works in the sciences. An engineer is someone who is trained as an engineer. So, to my way of thinking, the practical difference lies in the educational degree and the description of the task being performed by the scientist or engineer. On a more philosophical level, scientists tend to explore the natural world and discover new knowledge about the universe and how it works. Engineers apply that knowledge to solve practical problems, often with an eye toward optimizing cost, efficiency, or some other parameters. There is considerable overlap between science and engineering, so you will find scientists who design and construct equipment and engineers who make important scientific discoveries. Information theory was founded by Claude Shannon, a theoretical engineer. Peter Debye won the Nobel Prize in Chemistry with a degree in electrical engineering and a doctorate in physics. Do you feel there are important distinctions between scientists and engineers? You're invited to define the difference.

Words have precise meanings in science. For example, 'theory', 'law', and 'hypothesis' don't all mean the same thing. Outside of science, you might say something is 'just a theory', meaning it's supposition that may or may not be true. In science, a theory is an explanation that generally is accepted to be true. Here's a closer look at these important, commonly misused terms. Hypothesis A hypothesis is an educated guess, based on observation. Usually, a hypothesis can be supported or refuted through experimentation or more observation. A hypothesis can be disproven, but not proven to be true. Example: If you see no difference in the cleaning ability of various laundry detergents, you might hypothesize that cleaning effectiveness is not affected by which detergent you use. You can see this hypothesis can be disproven if a stain is removed by one detergent and not another. On the other hand, you cannot prove the hypothesis. Even if you never see a difference in the cleanliness of your clothes after trying a thousand detergents, there might be one you haven't tried that could be different. Theory A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing. A theory is valid as long as there is no evidence to dispute it. Therefore, theories can be disproven. Basically, if evidence accumulates to support a hypothesis, then the hypothesis can become accepted as a good explanation of a phenomenon. One definition of a theory is to say it's an accepted hypothesis. Example: It is known that on June 30, 1908 in Tunguska, Siberia, there was an explosion equivalent to the detonation of about 15 million tons of TNT. Many hypotheses have been proposed for what caused the explosion. It is theorized that the explosion was caused by a natural extraterrestrial phenomenon, and was not caused by man. Is this theory a fact? No. The event is a recorded fact. Is this this theory generally accepted to be true, based on evidence to-date? Yes. Can this theory be shown to be false and be discarded? Yes. Law A law generalizes a body of observations. At the time it is made, no exceptions have been found to a law. Scientific laws explain things, but they do not describe them. One way to tell a law and a theory apart is to ask if the description gives you a means to explain 'why'. Example: Consider Newton's Law of Gravity. Newton could use this law to predict the behavior of a dropped object, but he couldn't explain why it happened. As you can see, there is no 'proof' or absolute 'truth' in science. The closest we get are facts, which are indisputable observations. Note, however, if you define proof as arriving at a logical conclusion, based on the evidence, then there is 'proof' in science. I work under the definition that to prove something implies it can never be wrong, which is different. If you're asked to define hypothesis, theory, and law, keep in mind the definitions of proof and of these words can vary slightly depending on the scientific discipline. What is important is to realize they don't all mean the same thing and cannot be used interchangeably.

Yes, can candle can burn in zero gravity. However, the flame is quite a bit different. Fire behaves differently in space and microgravity than on Earth. A microgravity flame forms a sphere surrounding the wick. Diffusion feeds the flame with oxygen and allows carbon dioxide to move away from the point of combustion, so the rate of burning is slowed. The flame of a candle burned in microgravity is an almost invisible blue color (video cameras on Mir could not detect the blue color). Experiments on Skylab and Mir indicate the temperature of the flame is too low for the yellow color seen on Earth. Smoke and soot production is different for candles and other forms of fire in space or zero gravity compared to candles on earth. Unless air flow is available, the slower gas exchange from diffusion can produce a soot-free flame. However, when burning stops at the tip of the flame, soot production begins. Soot and smoke production depends on the fuel flow rate. It isn't true that candles burn for a shorter length of time in space. Dr. Shannon Lucid (Mir), found that candles that burn for 10 minutes or less on Earth produced a flame for up to 45 minutes. When the flame is extinguished, a white ball surrounding the candle tip remains, which may be a fog of flammable wax vapor.

Whether you add acid to the water or water to the acid is one of those things I know it's important to remember, but always have to puzzle out. Sulfuric acid (H2SO4) reacts very vigorously with water, in a highly exothermic reaction. If you add water to concentrated sulfuric acid, it can boil and spit and you may get a nasty acid burn. If you spill some sulfuric acid on your skin, you want to wash it off with copious amounts of running cold water as soon as possible. Water is less dense than sulfuric acid, so if you pour water on the acid, the reaction occurs on top of the liquid. If you add the acid to the water, it sinks and any wild and crazy reactions have to get through the water or beaker to get to you. How do you remember this? Here are some mnemonics: * AA - Add Acid * Acid to Water, like A&W Root Beer * Always do things as you oughta, add the acid to the water. (um... no... those words don't rhyme in most places.) * Drop acid, not water. (Don't do that either, ok?) * If you think your life's too placid, add the water to the acid. Personally, I don't find any of those mnemonics easy to remember. I get it right because I figure if I get it wrong, I'd rather have a whole container of water splash on me than a whole container of sulfuric acid, so I take my chances with the small volume of acid and the large volume of water.

Dmitri Mendeleev is credited with making the first periodic table that resembles the modern periodic table. His table ordered the elements by increasing atomic weight (we use atomic number today). He could see recurring trends, or periodicity, in the properties of the elements. His table could be used to predict the existence and characteristics of elements that hadn't been discovered. When you look at the modern periodic table, you won't see gaps and spaces in the order of the elements. New elements aren't exactly discovered anymore. However, they can be made, using particle accelerators and nuclear reactions. A new element is made by adding a proton (or more than one) to a pre-existing element. This can be done by smashing protons into atoms or by colliding atoms with each other. The last few elements in the table will have numbers or names, depending on which table you use. All of the new elements are highly radioactive. It's difficult to prove that you have made a new element, because it decays so quickly. Encyclopedia of Chemistry | Recent Chemistry Features

Detergents and soaps are used for cleaning because pure water can't remove oily, organic soiling. Soap cleans by acting as an emulsifier. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War I and World War II. Detergents are primarily surfactants, which could be produced easily from petrochemicals. Surfactants lower the surface tension of water, essentially making it 'wetter' so that it is less likely to stick to itself and more likely to interact with oil and grease. Modern detergents contain more than surfactants. Cleaning products may also contain enzymes to degrade protein-based stains, bleaches to de-color stains and add power to cleaning agents, and blue dyes to counter yellowing. Like soaps, detergents have hydrophobic or water-hating molecular chains and hydrophilic or water-loving components. The hydrophobic hydrocarbons are repelled by water, but are attracted to oil and grease. The hydrophilic end of the same molecule means that one end of the molecule will be attracted to water, while the other side is binding to oil. Neither detergents nor soap accomplish anything except binding to the soil until some mechanical energy or agitation is added into the equation. Swishing the soapy water around allows the soap or detergent to pull the grime away from clothes or dishes and into the larger pool of rinse water. Rinsing washes the detergent and soil away. Warm or hot water melts fats and oils so that it is easier for the soap or detergent to dissolve the soil and pull it away into the rinse water. Detergents are similar to soap, but they are less likely to form films (soap scum) and are not as affected by the presence of minerals in water (hard water). Modern detergents may be made from petrochemicals or from oleochemicals derived from plants and animals. Alkalis and oxidizing agents are also chemicals found in detergents. Here's a look at the functions these molecules serve: * Petrochemicals/Oleochemicals These fats and oils are hydrocarbon chains which are attracted to the oily and greasy grime. * Oxidizers Sulfur trioxide, ethylene oxide, and sulfuric acid are among the molecules used to produce the hydrophilic component of surfactants. Oxidizers provide an energy source for chemical reactions. These highly reactive compounds also act as bleaches. * Alkalis Sodium and potassium hydroxide are used in detergents even as they are used in soapmaking. They provide positively charged ions to promote chemical reactions.

To balance redox reactions, assign oxidation numbers to the reactants and products to determine how many moles of each species are needed to conserve mass and charge. First, separate the equation into two half-reactions, the oxidation portion and the reduction portion. This is called the half-reaction method of balancing redox reactions or the ion-electron method. Each half-reaction is balanced separately and then the equations are added together to give a balanced overall reaction. We want the net charge and number of ions to be equal on both sides of the final balanced equation. For this example, let's consider a redox reaction between KMnO4and HI in an acidic solution: MnO4- + I- → I2 + Mn2+

Water in nature is rarely pure in the ``distilled water'' sense; it contains dissolved salts, buffers, nutrients, etc., with exact concentrations dependent on local conditions. Fish (and plants) have evolved over millions of years to the specific water conditions in their native habitats and may be unable to survive in significantly different environments. Beginners (especially the lazy) should take the easy approach of selecting fish whose needs match the qualities of their normal tap water. Alternatively, an advanced (and energetic!) aquarist can change the water characteristics to match the fish's needs, though doing so is almost always more difficult than first appears. In either case, you need to know enough about water chemistry to ensure that the water in your tank has the right properties for the fish you are keeping. Water has four measurable properties that are commonly used to characterize its chemistry. They are pH, buffering capacity, general hardness and salinity. In addition, there are several nutrients and trace elements.

Here's How: 1. First form a mixture. Stir some iron filings and sulfur together to form a powder. You have just taken two elements and combined them to form a mixture. You can separate the components of the mixture by stirring the powder with a magnet (iron will stick to it) or by swirling the powder with the magnet under the container (the iron will fall toward the magnet at the bottom - this is less messy). 2. If you heat the mixture over a bunsen burner, hot plate, or stove, the mixture will start to glow. The elements will react and will form iron sulfide, which is a compound. Careful! Unlike the mixture, the formation of a compound can't be undone so easily. Use glassware that you don't mind ruining. Tips: 1. When you form a mixture, you can add components in any ratio that you want. It doesn't matter if there is more iron than sulfur, for example. 2. When you form a compound, the components react according to a set formula. If there is an excess of one or the other, it will remain after the reaction that forms the compound. For example, you may have some leftover iron or sulfur in the tube with your mixture. 2 g of sulfur with 3.5 g of iron filings will completely react.

The smoke bomb you would purchase from a fireworks store usually is made from potassium chlorate (KClO3 - oxidizer), sugar (sucrose or dextrin - fuel), sodium bicarbonate (otherwise known as baking soda - to moderate the rate of the reaction and keep it from getting too hot), and a powdered organic dye (for colored smoke). When a commercial smoke bomb is burned, the reaction makes white smoke and the heat evaporates the organic dye. Commercial smoke bombs have small holes through which the smoke and dye are ejected, to create a jet of finely dispersed particles. Crafting this type of smoke bomb is beyond most of us, but you can make an effective smoke bomb quite easily. There are even colorants you can add if you want to make colored smoke. Let's start out with instructions for the easiest/safest type of smoke bomb you can make: Smoke Bomb Materials * sugar (sucrose or table sugar) * potassium nitrate, KNO3, also known as saltpeter (buy it online or you can find this at some garden supply stores in the fertilizer section, some pharmacies carry it too) * skillet or pan * aluminum foil Once you've gathered your smoke bomb materials, it's easy to make the smoke bomb...

1 of 4 Prev Next Disappearing Ink Chemistry Disappearing ink is a water-based acid-base indicator (pH indicator) that changes from a colored to a colorless solution upon exposure to air. The most common pH indicators for the ink are thymolphthalein (blue) or phenolphthalein (red or pink). The indicators are mixed into a basic solution that becomes more acidic upon exposure to air, causing the color change. Note that in addition to disappearing ink, you could use different indicators to make color-change inks, too.

Happy Henry Likes Beer But Could Not Obtain Food for: 1. H - hydrogen 2. He - helium 3. Li - lithium 4. Be - beryllium 5. B - boron 6. C - carbon 7. N - nitrogen 8. O - oxygen 9. F - fluorine

Recrystallization is a laboratory technique used to purify solids based on their different solubilities. A small amount of solvent is added to a flask containing an impure solid. The contents of the flask are heated until the solid dissolves. Next, the solution is cooled. A more pure solid precipitates, leaving impurities dissolved in the solvent. Vacuum filtration is used to isolate the crystals. The waste solution is discarded. Summary of Recrystallization Steps 1. Add a small quantity of appropriate solvent to an impure solid. 2. Apply heat to dissolve the solid. 3. Cool the solution to crystallize the product. 4. Use vacuum fitration to isolate and dry the purified solid. Let's take a look at the details of the recrystallization process.

Here's How: 1. Find a clean surface on the specimen to be tested. 2. Try to scratch this surface with the point of an object of known hardness, by pressing it firmly into and across your test specimen. For example, you could try to scratch the surface with the point on a crystal of quartz (hardness of 9), the tip of a steel file (hardness about 7), the point of a piece of glass (about 6), the edge of a penny (3), or a fingernail (2.5). If your 'point' is harder than the test specimen, you should feel it bite into the sample. 3. Examine the sample. Is there an etched line? Use your fingernail to feel for a scratch, since sometimes a soft material will leave a mark that looks like a scratch. If the sample is scratched, then it is softer than or equal in hardness to your test material. If the unknown was not scratched, it is harder than your tester. 4. If you are unsure of the results of the test, repeat it, using a sharp surface of the known material and a fresh surface of the unknown. 5. Most people don't carry around examples of all ten levels of the Mohs hardness scale, but you probably have a couple of 'points' in your possession. If you can, test your specimen against other points to get a good idea of its hardness. For example, if you scatch your specimen with glass, you know its hardness is less than 6. If you can't scratch it with a penny, you know its hardness is between 3 and 6. The calcite in this photo has a Mohs hardness of 3. Quartz and a penny would scratch it, but a fingernail would not. Tips: 1. Try to collect examples of as many hardness levels as you can. You can use a fingernail (2.5), penny (3), piece of glass (5.5-6.5), piece of quartz (7), steel file (6.5-7.5), sapphire file (9). What You Need: * unknown specimen * objects of known hardness (e.g., coin, fingernail, glass)

The meniscus is the curve seen at the top of a liquid in response to its container. The meniscus can be either concave or convex. A concave meniscus (e.g., water in glass) occurs when the molecules of the liquid are more strongly attracted to the container than to each other. A convex meniscus (e.g., mercury in glass) is produced when the molecules of the liquid are more strongly attracted to each other than to the container. In some cases, the meniscus appears flat (e.g., water in some plastics). When you read a scale on the side of a container with a meniscus, such as a graduated cylinder or volumetric flask, it's important that the measurement accounts for the meniscus. Measure so that the line you are reading is even with the center of the meniscus. For water and most liquids, this is the bottom of the meniscus. For mercury, take the measurement from the top of the meniscus. In either case, you are measuring based on the center of the meniscus.

Before You Take the Test 1. Get Some Rest A good night's sleep is ideal. If you can't manage that, try for at least a few hours. 2. Eat Breakfast Even if your test is later in the day, breakfast can help with your test outcome. A light, high-protein meal is recommended. 3. Arrive Early Get to the test center early enough to get comfortable and relaxed. 4. Prepare Your Materials Make sure you have pencils, a watch, a calculator (with good batteries), test forms, and any other required supplies. 5. Relax Take a few deep breaths. 6. Have a Positive Attitude Don't psych yourself into failure. When You Get the Test 1. Download What You Know For science tests, such as chemistry and physics, you may have memorized constants and equations. Write these down. Write down anything you remember that you feel you may forget during the test. 2. Preview the Test Scan the test and identify the high-point questions. Also look for easy questions. Mark questions about which you are unsure to skip over until later. 3. Read the Instructions Don't assume you know how to answer a question until you read the directions. Taking the Test 1. Get Started Start with a high-point question you can answer. 2. Budget Your Time Work through the test from highest to lowest point value, answering questions about which you feel confident. In some cases, you may want to write an answer that covers the important points, then go back later to expand on your answer and provide examples. 3. Answer All Questions ...unless you are penalized for quessing. If you are penalized for wrong answers, eliminate answers you know are incorrect, then make a guess (if you have eliminated enough answers to risk the guess). 4. Be Sure You Answered All Questions Double-check for completeness. 5. Check Your Work If you have the time, this is very important. Science tests are notorious for problems in which answers depend on earlier sections. 6. Don't Second-Guess Yourself Don't change your answer unless you are sure of the new answer.

Here's How: 1. Write the author's last name, first name, and middle name or initial. Two authors are handled a little differently. For example, you would write: Helmenstine, A.M. and John R. Smith, Cool Chemistry Projects, New York: Sterling Pub. Co., Aug. 2005, pp. 1-15. 2. Write the name of the article or the chapter of your source in quotes. 3. Write and either underline or italicize the title of the book or source. 4. Write the place (city, state, country) where the source was published, followed by a colon. 5. Write the publisher's name, date of publication, and volume (if applicable), followed by a colon and the page numbers. The abbreviation for page is p.. The abbreviation for pages is pp.. Volume is vol.. 6. Organize your bibliography by writing your references in alphabetical order, according to the author's last name. Tips: 1. Here is an example for a book or magazine -- Jones, Jenny R., "Science Experiments to Try" Science Time, New York: Sterling Pub. Co., May 2004, Vol. 3:12-15. 2. Here is an example for a Web site -- Helmenstine, Anne, About Chemistry Website, http://chemistry.about.com, Oct. 4, 2005. 3. Here is an example for a conversation -- Smith, John, Telephone Conversation, Mar. 5, 1993. 4. If your instructor has a different method to use for citing references, follow those guidelines. There is more than one correct way to write a bibliography. What You Need: * List of Sources - Alphabetized * Pen/Paper or Computer

Lab reports are an essential part of all laboratory courses and usually a significant part of your grade. If your instructor gives you an outline for how to write a lab report, use that. Here's a format for a lab report you can use if you aren't sure what to write or need an explanation of what to include in the different parts of the report. A lab report is how you explain what you did in experiment, what you learned, and what the results meant. Here is a standard format. If you prefer, you can print and fill in the science lab report template or download the pdf version of the template. 1. Title Page Not all lab reports have title pages, but if your instructor wants one, it would be a single page that states: * The title of the experiment. * Your name and the names of any lab partners. * Your instructor's name. * The date the lab was performed or the date the report was submitted. 2. Title The title says what you did. It should be brief (aim for ten words or less) and describe the main point of the experiment or investigation. An example of a title would be: "Effects of Ultraviolet Light on Borax Crystal Growth Rate". If you can, begin your title using a keyword rather than an article like 'The' or 'A'. 3. Introduction / Purpose Usually the Introduction is one paragraph that explains the objectives or purpose of the lab. In one sentence, state the hypothesis. Sometimes an introduction may contain background information, briefly summarize how the experiment was performed, state the findings of the experiment, and list the conclusions of the investigation. Even if you don't write a whole introduction, you need to state the purpose of the experiment, or why you did it. This would be where you state your hypothesis. 4. Materials List everything needed to complete your experiment. 5. Methods Describe the steps you completed during your investigation. This is your procedure. Be sufficiently detailed that anyone could read this section and duplicate your experiment. Write it as if you were giving direction for someone else to do the lab. It may be helpful to provide a Figure to diagram your experimental setup. 6. Data Numerical data obtained from your procedure usually is presented as a table. Data encompasses what you recorded when you conducted the experiment. It's just the facts, not any interpretation of what they mean. 7. Results Describe in words what the data means. Sometimes the Results section is combined with the Discussion (Results & Discussion). 8. Discussion or Analysis The Data section contains numbers. The Analysis section contains any calculations you made based on those numbers. This is where you interpret the data and determine whether or not a hypothesis was accepted. This is also where you would discuss any mistakes you might have made while conducting the investigation. You may wish to describe ways the study might have been improved. 9. Conclusions Most of the time the conclusion is a single paragraph that sums up what happened in the experiment, whether your hypothesis was accepted or rejected, and what this means. 10. Figures & Graphs Graphs and figures must both be labeled with a descriptive title. Label the axes on a graph, being sure to include units of measurement. The independent variable is on the X-axis. The dependent variable (the one you are measuring) is on the Y-axis. Be sure to refer to figures and graphs in the text of your report. The first figure is Figure 1, the second figure is Figure 2, etc. 11. References If your research was based on someone else's work or if you cited facts that require documentation, then you should list these references.

Thermal energy refers to the energy that is caused by heat. Thermal electrical engineers manage the heat that is created by electronics and electrical systems. When working with Thermal Electrical Engineering, engineers will model energy systems and heat-mass transfer in order to learn how to cool systems efficiently. An Overview of Thermal Electrical Engineering Electrical engineers work with electronics and electrical systems to design machinery, wiring systems and motors. Dealing with the heat or thermal energy generated by electrical systems is an important aspect of an electrical engineer's job. Although most machines and electrical systems generate heat, the heat may not be needed for a machine to work. Thermal electrical engineers determine how to cool systems and prevent them from overheating. The Thermoelectric Effect The thermoelectric effect is a key concept that forms the foundation of Thermal Electrical Engineering. It refers to the conversion of temperature differences into electrical voltage. The thermoelectric effect covers the science underlying cooking, heating, cooling, generating electricity and measuring temperature. The thermoelectric effect is comprised of three components: * Seebeck Effect: The Seebeck Effect is a temperature difference between two dissimilar materials or conductors causes a current to flow through the circuit. * Peltier Effect: The Peltier Effect is the phenomenon that defines the temperature difference that arises when an element from the thermoelectric series has wires connected to it to form a circuit. * Thompson Effect: The Thompson Effect occurs when a conductor that is unevenly heated causes heat to flow into or out of the material when electrical currents flow between the two points. Applications of Thermal Electrical Engineering Thermal electrical engineers must possess practical experience in the development, construction and operation of thermal energy conversion systems and components, typically gained in lab settings and in real-world applications. They must use their knowledge of various methods, functions and relationships between systems and diverse components of thermal energy conversion technology to formulate solutions for numerous purposes, including heating or cooling of various processes, equipment or encased settings: * Microprocessors * Electronic equipment * Power plants * Thermal system and imaging equipment * Thermal Storage systems - hot water tanks and air conditioning systems

If you are considering a graduate degree in electrical engineering, you likely hold a bachelor's degree in a science, engineering, mathematics or computer-related discipline. Because admission into graduate engineering programs can be competitive, you need to maintain a grade point average of 3.0 or higher during your undergraduate years. Some programs require applicants to have taken specific undergraduate coursework, typically in math, computer science and engineering. Other requirements may include GRE scores, letters of recommendation and a passing score on a proficiency exam. Doctoral degree programs may expect you to have a master's degree in electrical engineering or a related subject.

Through some programs, you may be able to earn a Master of Science or Doctor of Philosophy in Electrical Engineering without specializing; however, many schools encourage you to choose a particular area of concentration. What concentration you choose can depend on the particular degree programs offered by the school as well as your individual interests and career objectives. Concentration options may include the following: * Electromagnetics * Nanotechnology * Electronics * Communications * Computer science

In general, a graduate degree program in electrical engineering requires core classes in advanced science, mathematics, computer technology and digital communication. The electives you choose will be contingent on your area of concentration. You may be given a choice between a writing a thesis or complete a major project. If you are pursuing a doctoral degree, you will likely have to pass comprehensive exams, as well as authoring and defending a dissertation.

There are schools that offer graduate degree programs both online and in hybrid format; hybrid programs require you to complete some of your coursework on campus. Typically, you need a computer with an Internet connection to participate in most online classes. Additional engineering-related software requirements may apply on an individual class basis.