What type of bonding holds two hydrogen atoms together?

covalent bond

Explanation:

A covalent bond is formed when two atoms share one or more pairs of electrons. The condition for the bond to have a high covalent character is that the difference in electronegativity between both atoms is zero or very small. According to Lewis's theory the bond that gives rise to the hydrogen molecule can be described as follows:

H ·  +  · H   ⇒   H  :  H

H - H

Both electrons are shared by the two atoms. For simplicity it is customary to represent the pair of electrons shared by a line (H-H)