Question: what is the atomic number of ammonium?
Answer: Explanation: In an ammonium ion (NH+4) ion, there is one nitrogen atom and four hydrogen atoms. Nitrogen has an atomic number of 7 , and hydrogen has an atomic number of 1 , and so the total atomic number of the hydrogens will be 1⋅4=4 . So, there will be a total of 7+4=11 protons.