Question

Two elements with electronic configuration of X is 2, 8, 1 and Y is 2,8,7 identify which element has bigger atomic size and why

Answer 1

X is sodium

Y is chlorine.

Obviously, size of sodium (X) is greater because atomic size increases on moving from right to left in a period.

Answer 2

Hey dear!
Here's your answer..

X has bigger atomic size because in the periodic table on moving from left to right in a period, the size of atoms decreases...

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