The number 4.0 × 10^5 has ___ significant figures.

• A. 1
• B. 5
• C. 2
• D. 3

Answer: (C)

Verified step by step guidance

1. Identify the number given: \$4.0 \times 10^{5}$.
2. Recall that in scientific notation, all digits in the coefficient (the number before the exponent) are significant.
3. Look at the coefficient '4.0': the digit '4' is significant, and the digit '0' after the decimal point is also significant because it indicates precision.
4. Count the significant figures in the coefficient: there are 2 significant figures ('4' and '0').
5. Therefore, the number \$4.0 \times 10^{5}$ has 2 significant figures.