How are elements in the same group of the periodic table similar to each other chemically?

Question

These elements all have the same number of energy levels with electrons in them.

These elements all have the same number of electrons in their inner shell.

These elements all have the same number of electrons.

These elements all have the same number of valence electrons.

choose the correct answer

Answer 1

The correct answer is:

These elements all have the same number of valence electrons.

Elements in the same group (or column) of the periodic table have the same number of valence electrons, which leads to similar chemical properties and reactivity.