Lithium (Li)
Atomic Number: 3
Atomic Mass: 6.941 amu
3 protons, 3 electrons, 4 neutrons
Magnesium (Mg)
Atomic Number: 12
Atomic Mass: 24.305 amu
12 protons, 12 electrons, 12 neutrons
Oxygen (O)
Atomic Number: 8
Atomic Mass: 15.9994 amu
8 protons, 8 electrons, 8 neutrons
Hope this helps!
