Answer
(a) 4 Significant Figures.
(b) 2 Significant Figures.
(c) 3 Significant Figures.
Work Step by Step
1. Identify and count the significant zeros:
(a) - All zeros between two nonzero digits are significant.
$1.6\underline 0 7 \space kg$
(b) - If there is no decimal point, all zeros to the right of the last nonzero digit are not significant.
$130 \space mcg$
(c) - All zeros between two nonzero digits are significant.
$4. \underline 0 2\times 10^6 $
2. Add this number to the amount of nonzero digits:
(a) 3 + 1 = 4
(b) 2 + 0 = 2
(c) 2 + 1 = 3
