What does it mean for the energy levels in an atom to be quantized? Describe how this affects where electrons can be found.

Energy of an electron is quantinized means the electrons can possess only specific individually separated values.

These energy levels are stable and are stationary along with different energy value.  The electron remains in the state until energy is absorbed or released.

The electrons absorb energy when it moves from lower energy state to higher energy state. The electrons lose energy when it moves from higher energy state to lower energy state and thus emit radiations corresponding to the energy gap and is called as quanta.

the answer would be a

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.