Why is fusion preferred over fission?

Fusion is the binding together of two smaller atoms into a larger atom. Both are examples of nuclear chemistry and both produce large amounts of energy. There are two main advantages of fusion over fission. ... The other main advantage is that fusion does not produce radioactive, toxic waste products like fission does.

if two electrons have the same n, the same ℓ, and the same ml, then they are in the same orbital. the pauli exclusion principle states that no two identical fermions (a fancy word for electrons and other subatomic particles like electrons) may occupy the same quantum state in an atom simultaneously.