Question

How do spontaneous nuclear fission processes occur?

Answer 1

Spontaneous nuclear fission can occur by the emission of alpha and beta particles. Other mechanisms involve positrons and gamma rays.

ALPHA PARTICLES:

An alpha particle is a helium nucleus. The heavier elements usually decay by alpha emission. For example,

`""_92^238U → _90^234Th + _2^4He`

BETA PARTICLES:

A beta particle is an electron. Nuclei that have too few protons can decay by converting a neutron to a proton and emitting a beta particle. For example,

`""_15^32P → _16^32S + _-1^0e`

POSITRONS:

A positron is the antimatter counterpart of an electron. Nuclei that have too many protons can decay by converting a proton to a neutron and emitting a positron. For example,

`""_5^8B → _4^8Be + _1^0e`

GAMMA RAYS:

Gamma rays are high-energy photons. When a nucleus emits an alpha or beta particle, the new nucleus may have excess energy. It can release this excess energy by emitting gamma rays.

Thus, thorium-234 becomes more stable by releasing gamma rays and a beta particle.

`"_90^234Th → _91^234Pa + _-1^0e + γ`