Please answer my question below expert - Science - Structure of the Atom

Question

Please answer my question below expert

Ravjot Kaur · Accepted Answer

Dear student a) Chloride ion is formed when chlorine atom gains an
electron So, its configuration will be 2,8,8 b) The atomic number
of Chloride ion is 17 and the mass number is 35 c) Valency of
chlorine is 1, as its configuration is 2,8,7, there is a
requirement of 1 electron in the valence shell Regards