Question

This atom tends to gain an electron in its outer shell so that there are a total of 8 electrons. - The atoms of this element lose one electron and become cations. - The atoms of this element all have one proton. - __________ atoms all have 2 protons. A. Sodium B. Chlorine C. Helium D. Hydrogen

Answer 1

Answer:

D.  Helium

Explanation:

By definition, the atomic number of an element is the number of protons in its nucleus.  2 protons mean atomic number 2:  Helium.