Protons.
Atomic number is the equivalent of the number of protons in an atomic nucleus.
The atomic number in a given element is equivalent to the number of protons in the element.
The atomic number of an atom is equivalent to the number of protons in its nucleus.
The atomic number is an integer, equivalent to number of protons in the atomic nucleus.
The atomic number of magnesium is 12. The atomic number is equivalent to the number of protons and electrons in the atom.
In a neutral atom the atomic number is the equivalent to number of electrons and protons.
The atomic number of a chemical element is equivalent to the number of protons and electrons, in the neutral state.
Either the number of protons or the number of electrons in a neutral atom is equivalent to its atomic number.
mass number = number of protons + number of neutrons The atomic number is equivalent to number of protons.
Electrons or atomic number. The atomic number is the number of protons as well as the principle quantum number.
The atomic number is equivalent to the number of protons; the number of neutrons is different for each isotope.
The number of protons is equivalent to the Atomic Number.