Answer:
Chlorine-36 undergoes β-decay.
Explanation:
Cl-36 is radioactive. It emits an electron ( a β-particle) to become more stable and forms Ar-36.
The nuclear equation is
[tex]_{17}^{36}\text{Cl}\longrightarrow_{-1}^{0}\text{e} + _{18}^{36}\text{Ar}[/tex]