Question

In which of the following pairs do both numbers contain the same number of significant figures?

150000 s and 1.50×10⁴s

405 K and 405.0 K

0.00575 g 5.75×10^-3g

3.8×10^-2 L and 3.0×10⁵ L

Answer 1

Follow the following guidelines to find out the significant numbers because only significant numbers involve measurement decisions:

(a) non zero digits are always significant, (b) any zeros between two significant digits are significant and (c) a final zero or trailing zeros in the decimal portion only are significant.

Based on these guidelines last two pairs have same significant numbers

150000 s and 1.50×10⁴s   (two and three significant numbers)

405 K and 405.0 K             (three and four significant numbers)

0.00575 g and 5.75×10^-3g (three and three significant numbers)

3.8×10^-2 L and 3.0×10⁵ L   (two and two significant numbers)