Why is the first ionization energy for sodium smaller than the second?

[Pechy]

WHy is the first ionization energy for sodium much smaller than the secon ionization energy for sodium? i don't understand this.

 

[Hootenanny]

Hi there Pechy and welcome to PF,

Why do you think it is? Think about shell configuration and atomic charge.

 

[lightgrav]

Shell configuration ??
Atomic charge total is zero ... the ionized sodium is a positive ION.

THAT is the main reason the second electron is much harder to remove ...
for ANY object, not just a sodium atom/ion.