Question

Out of Na and Na+ which one has larger size and why?

Answer 1

when the element loses electron (turn into cation, with positive charge), the atom radius is getting low, so obviously Na is larger than Na+

Answer 2

1) The atomic number of sodium is 1 and it has 11 protons and 11 electrons with outer electron as 3s1 whereas Na+ ion has 11 protons but only 10 electrons.

2) The 3s shell of Na+ has no electrons in it.

3) So the outer shell configuration is 2s2 2p6.

4) As proton number is more than electrons,the nucleus of Na+ ion attracts outer shell electrons with strong nuclear force.

5) As a result the Na+ ion shrinks in size.

6) Therefore, the size of Na+ ions is less than Na atom.(Na -157 pm and Na+ is 98pm)