Question

The process in which the nucleus of an atom splits into two lighter atoms, releasing a large amount of energy, is nuclear .

Answer 1

It's nuclear fission

Answer 2

Answer: fission

Explanation:

Nuclear fusion is a process which involves the conversion of two small nuclei to form a heavy nuclei along with release of energy.

$4_1^1\textrm{H}\rightarrow _2^4\textrm{He}+2_{+1}^0\textrm{e}+\text{energy}$

Nuclear fission is a process which involves the conversion of a heavier nuclei into two or more small and stable nuclei along with the release of energy.

$_{92}^{235}\textrm{U}+_0^1\textrm{n}\rightarrow _{56}^{143}Ba+_{36}^{90}Kr+3_0^1\textrm{n}$

Thus if a heavier nuclei is converted into two smaller nuclei, this is a nuclear fission reaction.