Question

Na ion is smaller than Na atom and Al ion is bigger than Al atom. why?

Answer 1

Hey there :

Na + is smaller than Na atoms b'coz . Na + is formed when an electron is lost from Na atom .Thus the effective nuclear charge increases b'coz no. of protons exceeds the no. of electron ...............&  Al + ion is bigger than Al atom , Al commonly forms 3+ ions  .An Al3+ ion has 3 fewer electrons than Al atom, but same no of protons . therefore  the ion will be smaller as its outer electrons are closer to nucleus ............

HOPE YOU UNDERSTAND .............