Answer to Question #149630 in General Chemistry for Ameya

Question

Put an aluminum atom, Al (aluminum) and an aluminum ion, Al^3+ in increasing (smallest to greatest) order. (Enter "Al" or "Al^3+" first, then enter a semicolon, then enter one space and then enter "Al" or "Al^3+" second.)

Answer 1

$Al^{3+} ; Al$

Al3+ is smaller than Al because;

The electronic configuration of Al is 1s2 2s2 2p6 3s2 3p1.

When Al loses 3 electrons to become Al3+, it no longer has its 3rd shell (L Shell) making it smaller in size as a result when compared to the Al atom which has 3 shells.