What is the valency and number of valence electrons in ³⁵Cl₁₇ respectively?

The number of valence electrons in ³⁵Cl₁₇ is 7.
The atomic number of chlorine = 17,
No of protons = 17,
No of electrons =17
Electronic configuration = 2, 8, 7
No. of valence electrons = 7
it will gain 1 electron to complete its octet
Hence, the valency and number of valence electrons in ³⁵Cl₁₇ respectively is 1 and 7.