Question

How many protons, neutrons, and electrons are there if manganese has an atomic number of 25, a mass number of 55, and a charge of +6?

Answer 1

Mn has 25 protons. 

Normally, it would also have 25 electrons. However, a charge of +6 indicates that it has 6 less electrons. Thus, this ion has 19 electrons. 

The number of neutrons is the mass number-the number of protons = 30 neutrons.