Question

how are elements in the same group on the current periodic table similar?
a. they have the same number of outermost electrons.
b. they have the same number of energy levels.
c. they have the same number of neutrons.
d. they have the same number of protons.

Explanation:

Elements in the same group of the periodic table have similar chemical properties because they have the same number of outermost electrons (valence electrons). The number of energy levels increases as you move down a group. Neutron and proton numbers vary among different elements in a group.

Answer:

A. They have the same number of outermost electrons.