A nuclear reaction releases 9.00 * 10^13 J of energy. What was the change in mass?

5.0 * 10^-4 kg

1.0 * 10^-3 kg

5.0 * 10^-3 kg

5.0 * 10^-2 kg

A nuclear reaction is the perfect place to use E = mc².

9.00 x 10¹³ = (m) (3 x 10⁸) ²

Divide each side by (3 x 10⁸) ² : m = (9 x 10¹³) / (3 x 10⁸) ²

m = (9 x 10¹³) / (9 x 10¹⁶) = 0.001 kg

Now, take several steps back, and look at what you've been working with:

You just showed that 1 gram of matter, when completely converted to energy,

produces the energy for a 100-watt light bulb to run for 28,519 years!