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Question
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
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Solution
Mass number A = n + p (atomic number)
A = n + Z
23 = n + 11
∴ n = 23 – 11 = 12
(1) Number of neutrons = 12
(2) e = p = 11
∴ Number of electrons e = 11
∴ Electron configuration of A = 2, 8, 1
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