Answer: A,C,D
Step-by-step explanation:
Element in the same group shared similar chemical behaviour and resemble each other because of the same number of valency electron they have. Example group one element have a valence electron of one.
Because of the same Valency electron they react in a similar way.
Example Group 1 have one valence electron and therefore Ionize readily to form positive electron this occur when they donate their valence electron leading to the formation of electrovalent compounds this is applicable for all group one element. Hence,
Elements in the same group have similar properties and react the same
Also, because element in the same group share the same property in chemical behaviour they are said to belong to one family.
Element in the same group do not have the same energy level because their electron tends to increases down the group and therefore energy level increases and not constant for all elements.