# How do beta emission and positron emission affect the neutron-proton ratio?

Sep 18, 2014

The neutron-proton ratio decreases during β⁻ decay and increases during positron decay,

β⁻ EMISSION

β⁻ emission is a process in which a nucleus emits an electron.

For example, neon-23 decays into sodium-23 by β⁻ emission.

₁₀²³Ne → ₁₁²³Na + ₋₁⁰e

In neon-23, there are 13 neutrons and 10 protons. The neutron:proton ratio is 13:10 or 1.30:1.

In sodium-23, there are 12 neutrons and 11 protons. The neutron:proton ratio 12:11 or 1.09:1.

The neutron:proton ratio decreases during β⁻ decay.

POSITRON EMISSION

β⁺ or positron emission is a process in which a nucleus emits a positron — the antimatter counterpart of an electron.

Magnesium-23 decays by positron emission.

${\text{_12^23"Mg" → ""_11^23"Na" + }}_{1}^{0} e$

In magnesium-23, there are 11 neutrons and 12 protons. The neutron:proton ratio is 11:12 or 0.9:1.

In sodium-23, there are 12 neutrons and 11 protons. The neutron:proton ratio 12:11 or 1.09:1.

The neutron:proton ratio increases during positron decay.