Which of the following measurements has three significant figures?

• A. 45.00
• B. 0.0450
• C. 450
• D. 0.00450

Answer: (B)

Verified step by step guidance

1. Understand the concept of significant figures: Significant figures are the digits in a number that carry meaningful information about its precision. This includes all nonzero digits, any zeros between significant digits, and trailing zeros in the decimal portion.
2. Analyze each measurement to count its significant figures:
3. - For 45.00: The digits '4' and '5' are significant, and the two zeros after the decimal point are trailing zeros, which are significant. So, it has 4 significant figures.
4. - For 0.0450: The leading zeros before '4' are not significant; they only indicate the position of the decimal point. The digits '4', '5', and the trailing zero after '5' are significant. So, it has 3 significant figures.
5. - For 450: Without a decimal point, the trailing zero is ambiguous and usually not counted as significant, so it has 2 significant figures.
6. - For 0.00450: The leading zeros are not significant, but '4', '5', and the trailing zero are significant, giving 3 significant figures.