How many kilocalories does 4.67 x 10^-20 J contain?

• A. 1.12 x 10^-23 kcal
• B. 5.67 x 10^-21 kcal
• C. 2.34 x 10^-22 kcal
• D. 9.81 x 10^-24 kcal

Answer: (A)

Verified step by step guidance

1. Understand the conversion factor between joules and kilocalories. 1 kilocalorie (kcal) is equivalent to 4184 joules (J).
2. Set up the conversion equation using the given energy in joules: \( 4.67 \times 10^{-20} \text{ J} \).
3. Use the conversion factor to convert joules to kilocalories: \( \text{kcal} = \frac{\text{J}}{4184} \).
4. Substitute the given value into the conversion equation: \( \text{kcal} = \frac{4.67 \times 10^{-20} \text{ J}}{4184} \).
5. Perform the division to find the energy in kilocalories, ensuring to keep track of significant figures and scientific notation.