Source: Extra Practice

Four students measured a physical quantity and reported their results. Student A: 0.069000.06900, Student B: 0.00690.0069, Student C: 6.90×10−26.90 \times 10^{-2}, and Student D: 6.9×10−36.9 \times 10^{-3}. Which student's measurement has the maximum number of significant figures?

Options

Option A is correct

Student A

Option B

Student B

Option C

Student C

Option D

Student D

Explanation

Let us count the significant figures for each: Student A: 0.069000.06900 has 4 significant figures (leading zeros are not significant; trailing zeros in a decimal are). Student B: 0.00690.0069 has 2 significant figures. Student C: 6.90×10−26.90 \times 10^{-2} has 3 significant figures. Student D: 6.9×10−36.9 \times 10^{-3} has 2 significant figures. Thus, Student A's measurement has the maximum number of significant figures.