Question

I have a question, about trends in the periodic table. Mostly focusing on ionization energy. From going from right to left it increases as the atom's size decreases. Can someone explain why this happens? Like why does it increase as the size decreases Thank you.

Answer 1

It increases because the electrons are held tighter together by the higher effective nuclear charge. The electrons are held in lower energy orbitals and closer to the nucleus and more tightly bound and harder to remove from the atom.