Name Date Class. N 10 n. Thus, the temperature of the Sun, 15 million kelvins, is written as K in scientific notation.

Transcription

1

2

3

4

5 Name Date Class 53 MATH HANDBOOK TRANSPARENCY MASTER Scientific Notation 1 Use with Appendix B, Scientific Notation Scientists need to express small measurements, such as the mass of the proton at the center of a hydrogen atom ( kg), and large measurements, such as the temperature at the center of the Sun ( K). To do this conveniently, they express the numerical values of small and large measurements in scientific notation, which has two parts. A number in which only one digit is placed to the left of the decimal N 10 n An exponent of 10 by which the number is multiplied Thus, the temperature of the Sun, 15 million kelvins, is written as K in scientific notation. Positive Exponents Express in scientific notation. Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Each time the decimal place is moved one place to the left, Negative Exponents Express in scientific notation. Each time the decimal place is moved one place to the right, the exponent is increased by one. the exponent is decreased by one. Math Handbook Transparency Masters Chemistry: Matter and Change 91

6 Name Date Class 54 MATH HANDBOOK TRANSPARENCY WORKSHEET Scientific Notation 1. Express each of the following numbers in scientific notation. a Use with Appendix B, Scientific Notation b c d. 56 million e. 2/10 f g h i j. 12 thousandth 2. Express each of the following measurements in scientific notation. a. speed of light in a vacuum, m/s b. number of seconds in a day, s c. mean radius of Earth, 6378 km d. density of oxygen gas at 0 C and pressure of 101 kpa, g/ml Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. e. radius of an argon atom, m 92 Chemistry: Matter and Change Math Handbook Transparency Worksheets

7 Name 55 Scientists very often deal with very small and very large numbers, which can lead to a Pf confusion when counting zeros! We have learned to express these numbers as powers 10. Scientific notation takes the form of M x 1 On where 1 I M < 10 and 'n" represents the number of decimal places to be moved. Positive n indicates the standard form is a large number. Negative n indicates a number between zero and one. Example 1 : Convert 1,500,000 to scientific notation. We move the decimal point so that there is only one digit to its left, a total of 6 places., 1,500,000 = 1.5 x lo6 Example 2: Convert to scientific notation. For this, we move the decimal point 5 places to the right = 2.5 x 105 (Note that when a number starts out less than one, the exponent is always negative.) Convert the following to scientific notation. Convert the following to standard notation. 5. 2,2x105 = 10. 4x100 = chemistry IF8766 Fair, Inc.

8 Name Date Class 57 MATH HANDBOOK TRANSPARENCY MASTER Operations with Scientific Notation 2 Use with Appendix B, Operations with Scientific Notation Addition and Subtraction Before numbers in scientific notation can be added or subtracted, the exponents must be equal. Not equal Equal ( ) ( ) ( ) ( ) The decimal is moved to the left to increase the exponent. ( ) Multiplication When numbers in scientific notation are multiplied, only the number is multiplied. The exponents are added. Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. ( )( ) (2.00)(4.00) Division When numbers in scientific notation are divided, only the number is divided. The exponents are subtracted Math Handbook Transparency Masters Chemistry: Matter and Change 93

9 Name Date Class 58 MATH HANDBOOK TRANSPARENCY WORKSHEET Operations with Scientific Notation 2 Use with Appendix B, Operations with Scientific Notation 1. Perform the following operations and express the answers in scientific notation. a. ( ) ( ) ( ) ( ) ( ) ( ) ( ) b. ( ) ( ) ( ) ( ) ( ) ( ) ( ) c. ( ) ( ) ( ) ( ) ( ) ( ) ( ) d. ( ) ( ) ( ) ( ) ( ) ( ) ( ) e. ( ) ( ) ( ) ( ) ( ) ( ) ( ) f. ( ) ( ) ( ) ( ) ( ) ( ) ( ) Perform the following operations and express the answers in scientific notation. a. ( ) ( ) ( ) ( ) (4.3)(2.0) b. ( ) ( ) ( ) ( ) (6.0)(1.5) 10 3 ( 2) c. ( ) ( ) ( ) ( ) (1.5)(8.0) 10 2 ( 1) d. e. f / / / / ( )( ) /( )( ) 6.48/(2.4)(1.8) ( 2) Copyright Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. 94 Chemistry: Matter and Change Math Handbook Transparency Worksheets

10

11

12

13

14

15

16

17

18 Honors Chemistry Dimensional Analysis II Name Use dimensional analysis to convert each of the following measurements to its equivalent in the units given g to milligrams µg to kilograms mg to centigrams g to micrograms km to millimeters x 10 4 mm to centimeters x 10 8 µg to kilograms km 3 to cubic decimeters cm 3 to cubic meters mm 3 to cubic decimeters x 10 5 pg to nanograms km/hr to m/sec x 10 5 mm/s to km/hr x 10 4 g/cm 2 to kg/m x 10 8 m/s to miles/hr Identify the number of significant figures in the following measurements x 10 6 g mm cm eggs cm

19 Honors Chemistry Chapter One Practice Test Name This practice test does not have any experimental design questions on it. There will be experimental design questions on the actual test. Directions: 1) Quickly answer all of the questions that you immediately know the answer to, skipping the ones that require a lot of time or thought. 2) Next, answer the questions that require thought. 3) Finally, answer the questions that you are unsure of. Answer questions 1-4 using the heating curve shown below e Temp (Celsius) b c d a Time (s) 1. What is the boiling point of this substance? 2. What is the freezing point of this substance? 3. Identify the region in which a solid and a liquid coexist. 4. Identify the region in which the substance exists only as a solid. 5. Sketch in appropriately labeled boxes a model of molecules,, showing their different arrangement as a solid, a liquid, and a gas. 6. Does the following diagram represent an element, a compound, or a mixture? Explain.

20 Honors Chemistry Chapter One Practice Test Name 7. A 10-g sample of material A was placed in water, whereupon 4 g of it, B, dissolved. The remaining material, C, was placed in a second sample of water, but no change took place. The sample B had a sharp melting point and, after melting was electrolyzed to yield 1.5 g of D and 2.5 g of E, neither of which could be further broken down. The sample C was heated in air, it reacted completely to give 22 g of a gas, F. Upon cooling to -100 C, material F solidified. And upon warming it sublimed at precisely at -78 C. Identify each of the lettered materials as either definitely or probably and element, compound, or a mixture. 8. Which of the following describe physical properties and which describe chemical properties. a. Color b. Decomposition on heating c. Boiling point d. Hardness e. Change of color on exposure to air. 9. Which of the following statements describe physical changes, and which describe chemical changes? a. Fresh-cut apples turning brown b. A white solid forms when sodium chloride solution is added to silver nitrate solution c. Drying clothes d. Baking bread 10. Zinc metal dissolves in a hydrochloric acid solution. Solid sodium chloride, table salt, dissolves in water. How can it be demonstrated that the second change is an actual case of dissolving, while the first is a chemical reaction? 11. List the four general signs of chemical change. 12. Bob recorded the following measurements for the density lab. Gold cylinder #1 had a mass of 5.35 grams. Silver cylinder #3 had a volume of 34.4 ml. Identify one qualitative measurement and one quantitative measurement.

21 Honors Chemistry Chapter One Practice Test Name 13. Record the mass to the proper number of significant figures and estimate the uncertainty grams Record the volume to the proper number of significant figures and estimate the uncertainty Identify the number of significant figures in each of the following measurements a cm b. 1.0 x 10 3 g c ml d g 16. Complete the calculation and report the answer to the correct number of significant figures. a. 12 cm x cm = b. (2.2 x 10-3 m) x (1.40 x 10-6 ) = c g g = d g g g =

22 Honors Chemistry Chapter One Practice Test Name 17. Round the following numbers to the number of significant figures required. a g to three significant figures b to three significant figures 18. A solid has a volume of 1.23 cm 3. Its mass plus that of a massing boat is g; the massing boat weighs 0.03 g. Calculate the density of the solid to the proper number of significant figures. 19. Complete the following dimensional analysis problems. a cm to meters b kg to mg c x 10 3 cm/s to km/hr 20. Sandy recorded the following measurements for three different samples of silicon. Calculate the density of silicon (using the formula, slope, or linear regression method). If the actual density of silicon is 2.33 g/cm 3, calculate Sandy s percent error and the standard deviation for her set of density values. Show all work for credit. Sample Mass, g Final Volume, cm 3 Initial Volume, cm