Does the ratio of neutrons to protons in a nucleus increase, decrease or remain the same after the emission of an `alpha` - particle ?

Explanation

The ratio of neutrons to protons in a nucleus, increases after the emission of an `alpha`- particle.
E.g. : Taking, `overset(238)underset(92)(uu)overset(._(2)He^(4))rarr overset(234)underset(90)(lh)`
Before emission, the ratio of neutrons to protons
`= (A-Z)/(Z)=(238-92)/(92)=(144)/(92)=1.57`
After emission, the ratio of neutrons to protons
`= (234-90)/(90)=1.6`
As `1.6 gt 1.587`, After emission, the ratio of neutrons to protons increases.