Source: Extra Practice

Which of the following measurements has the least number of significant figures?

Options

Option A is correct

0.0007 s0.0007\text{ s}

Option B

7.000 s7.000\text{ s}

Option C

70.00 s70.00\text{ s}

Option D

7.007 s7.007\text{ s}

Explanation

Let's analyze each measurement: 0.0007 s0.0007\text{ s} has only 1 significant figure (leading zeros are not significant). 7.000 s7.000\text{ s} has 4 significant figures (trailing zeros after a decimal point are significant). 70.00 s70.00\text{ s} has 4 significant figures. 7.007 s7.007\text{ s} has 4 significant figures (zeros between non-zero digits are significant). Therefore, 0.0007 s0.0007\text{ s} has the least number of significant figures.