A laboratory measurement is recorded as 0.00450 g. How many significant figures does this measurement have?

• A. 4
• B. 3
• C. 2
• D. 5

Answer: (B)

Verified step by step guidance

1. Identify all the digits in the measurement 0.00450 g, including zeros.
2. Recall that leading zeros (zeros before the first nonzero digit) are not significant; they only indicate the position of the decimal point.
3. Count the digits starting from the first nonzero digit: in 0.00450, the digits 4, 5, and the trailing zero after 5 are significant.
4. Understand that trailing zeros after a decimal point are significant because they indicate precision in the measurement.
5. Conclude that the number 0.00450 has 3 significant figures: 4, 5, and the trailing zero.