EXPLANATION
- a) 2
- b) 4
- c) 5
- d) 7
ANSWER: c) 5
EXPLANATION:
The number of significant figures in a measurement is the number of digits that are known with certainty plus one digit that is estimated. In the measurement, 0.0070500 grams, the first four digits (0.007) are known with certainty, and the last digit (0) is estimated. Therefore, there are 5 significant figures in the measurement. So the answer is (c).
Here are the rules for determining the number of significant figures in a measurement:
All nonzero digits are significant.
Any zeros between nonzero digits are significant.
Leading zeros (zeros to the left of the first nonzero digit) are not significant.
Trailing zeros (zeros to the right of the last nonzero digit) are significant only if they are followed by a decimal point.
In the measurement, 0.0070500 grams, the leading zeros are not significant because they are to the left of the first nonzero digit. The trailing zeros are significant because they are followed by a decimal point. Therefore, there are 5 significant figures in the measurement.
