The number of positively charged particles or protons present in the nucleus of an atom of each element is called atomic number. It is denoted by z.
There is the positive charge on the nucleus due to the presence of protons in it.
The number of protons in the nucleus determines the number of positive charge in the nucleus.
The number of protons in one atom of an element is known as an atomic number.
The total number of protons and neutrons present in one atom of an element is called its atomic mass.