Question

Question 21
Will ${}_{35}Cl$ and ${}_{37}Cl$ have different valencies? Justify your answer.

Answer 1

No, ${}^{35}Cl$ and ${}^{37}Cl$ have same valency. ${}^{35}Cl$ and ${}^{37}Cl$ are the isotopes. So, they have the same number of protons and electrons and have the same atomic number viz. 17. Hence, their electronic configuration and valencies are also the same.
Electronic configuration = 2, 8, 7
Valency 8 - 7 = 1
Therefore, both of them have valency = 1