Decrease in atomic numebr is not observed during

Options

A. alpha emission
B. beta emission
C. positron emission
D. electron capture

Answer

B

Explanation

`._(Z)^(A)X rarr ._(Z-2)^(A-4)Y+._(2)^(4)` He (alpha emission)
During beta emission, neutron in the nucleus splits into protons and electron, the electron comes out of the nucleus as beta particles, leaving behind the proton leading to an increase to atomic number by one unit:
`._(Z)^(A)Xrarr._(Z+1)^(A)T+._(_1)^(0)e(beta` emission)
Positron (positive electorn) is an elementary particel with the same mass as the electron and an electric charge of equal magnitude but opposite sign:
`._(Z)^(A)Xrarr_(Z-1)^(A)M+._(+1)^(0)e` (positron emission)
During electorn capture, an electron from the inner shell enters into the nucelus and converts proton into neutron:
`p+e^(-) rarr `n
Thus, `._(Z)^(A)X +_(-0)^(0)e rarr _(Z-1)^(A)N`