UNIT # 1 Introduction Objectives Reading 1.1 Metric System 1.2 1.3 Scientific Notation 1.4 Dimensional Analysis 1.5 1.6 1.7 1.8 Problems 1 | 2 | 3

Unit #1 Measurements

Significant Figures

1. Determine the number of significant figures in the following measurements:

• (a) 30.240 cm have?
3 4 5

• (b) 0.00545 g have?
3 4 5

• (c) 1.00040
3 5 6

2. Perform the arithmetic operation and round off the answers to the correct number of significant figures:

• (a) (0.0022 g)/(3.45 mL)

6.377 x 10-4 g/mL
6.4 x 10-4 g/mL
6.38 x 10-4 g/mL

• (b) 84.35 g - 0.02345 g

8.4 x 101 g
84.3266 g
84.33 g

• (c) 65.5 g / (54.45 cm x 65.45 cm x 65.0006 cm)

0.000283 g/cc
0.00028 g/cc
0.00 g/cc

3. Express the following in scientific notation to three significant figures:

• (a) 670

67.0 x 101
6.7 x 102 g/mL
6.70 x 102 g/mL

• (b) 0.000006778

6.77 x 10-6
0.678 x 10-5
6.78 x 10-6

• (c) 4.35 x 105 + 3.432 x 104

4.69 x 105
7.78 x 105
3.86 x 104

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