Question

elements in the same group will have the same number of
energy levels
core electrons
valence electrons

Explanation:

In the periodic table, elements in the same group (vertical column) share similar chemical properties. This similarity is due to having the same number of valence electrons (outer - shell electrons). Valence electrons are crucial for chemical bonding. Energy levels (related to periods, horizontal rows) and core electrons (inner - shell electrons that are not involved in bonding as directly) do not determine group - based similarities in the same way.

Answer:

Valence Electrons