Question

elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?
○ how many protons and neutrons they have
○ which chemical properties they have
○ how many total electrons they have
○ which period they are most often found in

Explanation:

Alkaline earth metals are in group 2. Elements in the same group have the same number of valence electrons, which determines chemical properties. Protons/neutrons (and total electrons) vary across periods (as atomic number increases), and periods differ (they're in different periods). So chemical properties are most similar.

Answer:

which chemical properties they have