To find how many times more massive a plutonium atom is compared to a hydrogen atom, you can divide the mass of the plutonium atom by the mass of the hydrogen atom.
Given:
Mass of hydrogen atom = \(1.67 \times 10^{-24}\) grams
Mass of plutonium atom = \(4.05 \times 10^{-22}\) grams
Now, compute the ratio:
\[ \text{Ratio} = \frac{\text{Mass of plutonium}}{\text{Mass of hydrogen}} = \frac{4.05 \times 10^{-22}}{1.67 \times 10^{-24}} \]
Calculating this:
- Divide the coefficients:
\[ \frac{4.05}{1.67} \approx 2.426 \]
- Divide the powers of ten:
\[ \frac{10^{-22}}{10^{-24}} = 10^{2} \]
Combining these:
\[ \text{Ratio} \approx 2.426 \times 10^{2} \approx 2.43 \times 10^{2} \]
Thus, an atom of plutonium is approximately \(2.43 \times 10^{2}\) times more massive than an atom of hydrogen.
The correct answer is:
B. \(2.43 \times 10^{2}\)