Question

If an atom 'A' has atomic number 19 and mass number 39 state -- a. it's electronic configuration b. the number of valence electrons it possesses.

Answer 1

Explanation:

A.)electronic configration ( in shell) is 2,8,18,9,2

and in subshell is [ kr]4 d^1 5 s^2.

B.) no. of valence electron it possesses is 2

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