In the mid 1930s Enrico Fermi bombarded uranium with thermal neutrons and observed the release of a large amount of energy. This happened because the heavy uranium nucleus split into two lighter nuclei, releasing two or three neutrons along with a large amount of energy.

What is this process called?

Respuesta :

This process is known as nuclear fission. It’s what powers nuclear weaponry.

For your information, the sister process is known as fusion, where, logically, two or more atoms are combined to form a heavier one. This is the process that keeps the sun and all other stars running.
the correct answer is B) NUCLEAR FISSION 
 fission means to separate or come apart.
 fusion means to fuse together.