Question

One gram of hydrogen is converted into $0.993\text{grams}$ of helium in a thermonuclear reaction. The energy released is

• A. $63\times {10}^7\text{J}$
• B. $63\times {10}^{10}\text{J}$
• C. $63\times {10}^{14}\text{J}$
• D. $63\times {10}^{20}\text{J}$

Answer 1

The correct option is B $63\times {10}^{10}\text{J}$

Using rest mass energy equivalence,
$\Delta E=\Delta m{c}^2$
$\Delta m=(1.000-0.993)g=0.007g$

$\therefore \Delta E=0.007\times 9\times {10}^{16}mJ$
$\therefore \Delta E=63\times {10}^{13}mJ=63\times {10}^{10}J$