**
**In our Sun, hydrogen atoms are fused (squeezed together) to
create helium atoms. This is called **nuclear fusion**,
and it produces the Sun's energy.

1. What appears to be wrong with the nuclear fusion equation on the top right?

2. What is actually missing from the equation?

3. E = mc^{2} is a famous equation. What do
each of the letters in the equation represent?

4. Can you guess the difference between nuclear **
fusion** and nuclear **fission**?