Which of the following is the correct scientific notation for 0.000345?

• A. 3.45 × 10^{-4}
• B. 34.5 × 10^{-5}
• C. 3.45 × 10^{-5}
• D. 3.45 × 10^{4}

Answer: (A)

Verified step by step guidance

1. Identify the decimal number given: 0.000345.
2. To write a number in scientific notation, express it as a product of a number between 1 and 10 and a power of 10. So, move the decimal point in 0.000345 to the right until you get a number between 1 and 10.
3. Count how many places you moved the decimal point. For 0.000345, moving the decimal point 4 places to the right gives 3.45.
4. Since you moved the decimal point 4 places to the right, the exponent on 10 will be negative 4, because the original number is less than 1.
5. Write the number in scientific notation as \$3.45 \times 10^{-4}$.