Will `""^(35)Cl` and `""^(37)Cl` have different valencies? Justify your answer.

Explanation

No, `""^(35)Cl` and `""^(37)Cl` have same valency. `""^(35)Cl` and `""^(37)Cl` are the isotopes. So, they have same number of protons and electrons and have same atomic number viz. 17 Hence, their electronic configuration and valencies are also the same
Electronic configuration `= overset(K)(2), overset(L)(8), overset(M)(7)`
Valency 8-7 = 1
Therefore, both of them have valency = 1