<span>A. Helium </span>atomic number 2
hope it helps
5= chemicals
6= hormones
Don't know the other ones.
Answer:
just by making or answering the questions
The O-16 nucleus has a mass of 15.9905 amu, A proton has a mass of 1.00728 amu, a neutron has a mass of 1.008665amu, and 1amu is equivalent to 931 MeV of energy.