To determine the number of significant figures in each of the provided numbers, we follow these rules:
- All non-zero digits are significant.
- Any zeros between non-zero digits are significant.
- Leading zeros (zeros to the left of the first non-zero digit) are not significant.
- Trailing zeros in a number without a decimal point are not significant, while trailing zeros in a number with a decimal point are significant.
Now, let's analyze each of the given numbers:
(a) 0.000050: The leading zeros are not significant. The significant digits are "5" and the trailing zero. Therefore, it has 3 significant figures.
(b) 7000: Since there is no decimal point, the trailing zeros are not considered significant. Therefore, it has 1 significant figure.
(c) 8.004: All the digits are non-zero or zero between non-zero digits, which are significant. Therefore, it has 4 significant figures.
(d) 457,000: Without a decimal point, the trailing zeros are not significant. Thus, it has 3 significant figures.
(e) 900: Similar to example (b), since there is no decimal point, only the "9" is significant. Therefore, it has 1 significant figure.
(g) 3.8 moles of silver: Both digits are significant, so it has 2 significant figures.
In summary:
- (a) 3 significant figures
- (b) 1 significant figure
- (c) 4 significant figures
- (d) 3 significant figures
- (e) 1 significant figure
- (g) 2 significant figures