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# Number of valence electrons in $$Cl^-$$ ion are:(a) 16(b) 8(c) 17(d) 18

(b) 8

EXPLANATION

The atomic number of chlorine is 17.

So the electrons are distributed in different shells as follows:-

K-shell has 2 electrons;
L-shell has 8 electrons;
M-shell has 7 electrons;

Chlorine atom has 7 electrons in its outermost shell but $$Cl^-$$ has one extra electron and this electron comes in the last shell which is the M-shell, thus the last shell electrons or the valence electrons of $$Cl^-$$ is 8.