Sometimes before researchers there is such task: how to define amount of atoms of any given substance? Originally it can seem exclusively difficult, amount of atoms even in a tiny sample of any substance just grandiose. How to count them?
Atoms consist of subatomic particles — protons, neutrons and electrons. Protons represent positively charged particles which are in the center of atom, in its kernel. It is possible to calculate number of protons of isotope on atomic number of the corresponding chemical element.