3. magnesium and sulfur
hydrogen-1hydrogen-2carbon-12etc.
3carbon-hydrogenn 2carbon-hydrogenn 16carbon-oxygen
English physicist that found out that the number of protons is the same as the atomic number? yes cuz,Oxygen has 6 number of protons as well as it has 6 Atomic Number..Same with:Elements Atomic Number Number Of ProtonsHelium 2 2Carbon 6 6Neon 10 10Sodium 11 11Magnesium 12 12Chlorine 17 17Calcium 20 20There you go!By AJHH