What is the maximum number of covalent bonds an element with atomic number 8 can make with hydrogen?

Tina T asked: The element with atomic number 8 would need 2 electrons to fill its valence shell, where as hydrogen only needs 1 to fill its valence shell right? The answer to this is 2 maximum covalent bonds, but I cannot figure out why. Science savvy people heeeelp I have a bio 2 exam [...]