Question

multiple - choice question
why do elements in a group behave similarly?
they have the same number of valence electrons
they have the same number of protons
they have the same number of total electrons

Explanation:

Valence electrons are responsible for an element's chemical behavior. Elements in the same group have the same number of valence electrons, leading to similar chemical properties. The number of protons determines the element itself, and the total number of electrons varies with the element's position in the periodic - table and its charge state.

Answer:

They have the same number of valence electrons