Chemistry 152 @ Farmingdale

Chemistry 152 @ Farmingdale - Chem 152 Scientific Method...

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Chem 152 May 24, 2010 Scientific Method Develop a hypothesis: what you expect the result to be Experiment/Observation Conclusion on the basis of your findings/results Was your hypothesis verified or not? Numbers are exponential. .. (X×10 x ) 3752.6 = 3.752 × 10 3 0.00046 = 4.6 × 10 -4 Rules for exponents Whenever you add or subtract exponential numbers, you must solve for each side of the equation before completing the function: 2 2 + 4 3 = 4 + 12 = 16 Whenever you multiply exponential numbers, you add the exponents: y 2 × y 2 = y 4 Whenever you divide two exponential numbers, you subtract the exponents: x 2 ÷ x 2 = x 0 = 1 as long as x 0 Whenever you raise an exponent expression to a power, you multiply the exponents: (x 2 ) 4 = x 8 Significant Figures Zeroes before any number from 1 9 don’t count as significant figures Zeroes after any rational number are counted as significant figures These rules apply only to calculations and not measurements For measurements, your result is only limited by the precision of your equipment When performing addition pr subtraction, the result may only have as many digits after the decimal point as the number in the calculation with the least number of digits after the decimal point. When performing multiplication or division, the result may contain only as many significant figures as the least precise number in the calculation .0072 or 7.2 × 10 -3 = 2 significant figures 0.051 + 71.3 - 5.853 + 100.6 = 166.098 OR 166.1 3.051 × .51 × 0.007 ÷ 61.5 = 1.7710668293, but since the number with the least significant figures in the calculation is 0.007 with one significant number, the quotient can only have one so we round to 2 × 10 -4 If you move the decimal to the left , the exponent is positive . 4000 = 4 × 10 3 If the decimal is moved to the right , the exponent is negative . .0004 = 4 × 10 -4 o However, this is for numbers that are NOT in exponential form! o If they are in exponential form, the opposite holds true (+ exponent moves decimal to right and - moves to left) Units of measurement British Metric Length Foot Meter Mass Pound Gram Time Second Second Volume Gallon Liter

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International System of Units (SI) prefixes: Prefix Symbol 10 n Decimal yotta Y 1 × 10 24 1000000000000000000000000 zetta Z 1 × 10 21 1000000000000000000000 exa E 1 × 10 18 1000000000000000000 peta P 1 × 10 15 1000000000000000 tera T 1 × 10 12 1000000000000 giga G 1 × 10 9 1000000000 mega M 1 × 10 6 1000000 Million kilo k 1 × 10 3 1000 Thousand hecto h 1 × 10 2 100 Hundred deca da 1 × 10 1 10 Ten 1 × 10 0 1 One deci d 1 × 10 −1 0.1 Tenth centi c 1 × 10 −2 0.01 Hundredth milli m 1 × 10 −3 0.001 Thousandth micro μ 1 × 10 −6 0.000001 Millionth nano n 1 × 10 −9 0.000000001 pico p 1 × 10 −12 .000000000001 femto f 1 × 10 −15 .000000000000001 atto a 1 × 10 −18 .000000000000000001 zepto z 1 × 10 −21 .000000000000000000001
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This note was uploaded on 10/10/2010 for the course CHM 152 taught by Professor Purandare during the Summer '10 term at SUNY Farmingdale.

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Chemistry 152 @ Farmingdale - Chem 152 Scientific Method...

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