Which of the following elements has the highest atomic mass? Helium: 2 protons and 2 neutrons
Nitrogen: 7 protons and 7 neutrons
Oxygen: 8 protons and 8 neutrons
Hydrogen: 1 proton and no neutrons

Will give crown.

oxygen has the highest atomic mass.

C Oxygen

Explanation:

The answer would be C since the protons and the neutrons are somewhat the same number / similar. As well as the periodic table would have somewhere in the elements "box".

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.