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1.1 1.2 1.3

(a) Cd (b) Sb (a) silver

(c) Am (c) rhenium (d) cesium (e) argon (f) arsenic

(b) rhodium

(a) Ti, metal (d) Sc, metal

(b) Te, semimetal (e) At, semimetal

(c) Se, nonmetal (f) Ar, nonmetal

1.4 1.5

The three Acoinage metals@ are copper (Cu), silver (Ag), and gold (Au). (a) The decimal point must be shifted ten places to the right so the exponent is S10. The S result is 3.72 x 10 10 m. (b) The decimal point must be shifted eleven places to the left so the exponent is 11. The result is 1.5 x 1011 m. (a) microgram (b) decimeter (c) picosecond (d) kiloampere (e) millimole 5 o 5 x ( F _ 32) = x (98.6 _ 32) = 37.0 o C 9 9 K = o C + 273.15 = 37.0 + 273.15 = 310.2 K o

1.6

1.7

C=

1.8

(a) K = oC + 273.15 = S78 + 273.15 = 195.15 K = 195 K 9 9 (b) o F = ( x o C) + 32 = ( x 158) + 32 = 316.4o F = 316 o F 5 5 (c) oC = K S 273.15 = 375 S 273.15 = 101.85oC = 102oC 9 9 o F = ( x o C) + 32 = ( x 101.85) + 32 = 215.33o F = 215o F 5 5

1.9

d=

m 27.43 g = = 2.212 g/ cm 3 V 12.40 cm 3

1 mL = 6.32 mL 1.483 g

1.10

1.11

volume = 9.37 g x

The actual mass of the bottle and the acetone = 38.0015 g + 0.7791 g = 38.7806 g. The measured values are 38.7798 g, 38.7795 g, and 38.7801 g. These values are both close to each other and close to the actual mass. Therefore the results are both precise and accurate.

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Chapter 1 S Chemistry: Matter and Measurement _____________________________________________________________________________ 1.12 (a) 76.600 kg has 5 significant figures because zeros at the end of a number and after the decimal point are always significant. (b) 4.502 00 x 103 g has 6 significant figures because zeros in the middle of a number are significant and zeros at the end of a number and after the decimal point are always significant. (c) 3000 nm has 1, 2, 3, or 4 significant figures because zeros at the end of a number and before the decimal point may or may not be significant. (d) 0.003 00 mL has 3 significant figures because zeros at the beginning of a number are not significant and zeros at the end of a number and after the decimal point are always significant. (e) 18 students has an infinite number of significant figures since this is an exact number. S (f) 3 x 10 5 g has 1 significant figure. (g) 47.60 mL has 4 significant figures because a zero at the end of a number and after the decimal point is always significant. (h) 2070 mi has 3 or 4 significant figures because a zero in the middle of a number is significant and a zero at the end of a number and before the decimal point may or may not be significant. (a) Since the digit to be dropped (the second 4) is less than 5, round down. The result is 3.774 L. (b) Since the digit to be dropped (0) is less than 5, round down. The result is 255 K. (c) Since the digit to be dropped is equal to 5 with nothing following, round down. The result is 55.26 kg. 24.567 g

1.13

1.14

(a)

+ 0.044 78 g This result should be expressed with 3 decimal places. Since the 24.611 78 g

digit to be dropped (7) is greater than 5, round up. The result is 24.612 g (5 significant figures). (b) 4.6742 g / 0.003 71 L = 1259.89 g/L 0.003 71 has only 3 significant figures so the result of the division should have only 3 significant figures. Since the digit to be dropped (first 9) is greater than 5, round up. The result is 1260 g/L (3 significant figures), or 1.26 x 103 g/L. 0.378 mL

(c)

+ 42.3 mL _ 1.5833 mL 41.0947 mL

This result should be expressed with 1 decimal place. Since the

digit to be dropped (9) is greater than 5, round up. The result is 41.1 mL (3 significant figures). The level of the liquid in the thermometer is just past halfway between the 32oC and 33oC

1.15

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Chapter 1 S Chemistry: Matter and Measurement...