Browsing All posts tagged under »chemistry«

Interactive tool: Practice estimating relative sizes

August 26, 2010 by

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Interactive tool for practicing comparing two lengths, areas, and volumes. It is VERY TRICKY to judge how area and volume change with size. This tool gives you good practice. Good for physics problems to do with pressure, gravity, and other places where area or volume are important. Explore size estimation in one, two and three dimensions! Multiple levels of difficulty allow for progressive skill improvement.

Interactive tool: Curve fitting functions to data points (PhET / UCBoulder)

August 26, 2010 by

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Interactive tool for fitting a straight line or other curves to data points. Great supplement to any science lab course. Let's you see how data and mathematical models relate to each other. With your mouse, drag data points and their error bars, and watch the best-fit polynomial curve update instantly. You choose the type of fit: linear, quadratic, cubic, or quartic. The reduced chi-square statistic shows you when the fit is good. Or you can try to find the best fit by manually adjusting fit parameters.

How to: Conversions using the factor-label method (Wikipedia)

August 26, 2010 by

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Brief instructions and example showing how to convert between units (say, from mi to m) using conversion ratios. Converting from one dimensional unit to another is often somewhat complex and being able to perform such conversions is an important skill to acquire. The factor-label method, also known as the unit-factor method or dimensional analysis, is a widely used approach for performing such conversions

How to: Entering scientific notation on a calculator (TI)

August 26, 2010 by

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Short 'how to' showing how to enter scientific notation on a TI (Texas Instruments) calculator. Use the Enter Exponent or [EE] key to enter numbers in scientific notation. The [EE] key is used to denote x10 for numbers written in scientific notation. Note: TI calculators use the EE button. Some calculators use the Exp button. If you don't know how to use these, you will waste your time and on some problems you'll get the wrong answer.

Online tutorial: Scientific notation (UCel)

August 26, 2010 by

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Online tutorial on using scientific notation to describe and compute with really large and really small numbers. Great review! 17 short Flash tutorials delivered in a charming British female voice. Good graphics and examples moving step-by-step through the use of scientific notation.

Fact sheet: Using scientfic notation (Wikipedia)

August 26, 2010 by

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Well organized discussion of how to add, subtract, multiply, and divide using scientific notation, and how to convert between that and regular numbers. Note: calculators often use a different notation. The Wikipedia article has a nice little discussion showing how that works.

Fact sheet: Number prefixes used in the SI system (Wikipedia)

August 26, 2010 by

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Well organized tables showing what the number prefixes—micro, nano, mega, giga, etc—mean and how to replace them with numbers. Note: gigabyte, megabyte, kilobyte, use a slightly different meaning for the prefixes. This can be a little confusing. The Wikipedia article has a nice little discussion of the difference between that and the SI usage.