What determines the atomic number of an element?

The number of protons in the nucleus of an atom of this element will determine its atomic number. Only this. If the atom is not charged (in other words, not an ion), this is the same as the number of electrons in the atom. In that case, the number of electrons will be the same as the number of protons. read more

atomic number. The number of protons in an atomic nucleus; it indicates the position of an element in the periodic table. The number of protons in the nucleus of an atom. In electrically neutral atoms, this number is also equal to the number of electrons orbiting about the atom's nucleus. read more

The number of protons in an atomic nucleus determines which element an atom is. For example: If the number of protons in an atom is 6, it is carbon. read more

The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom. It is identical to the charge number of the nucleus. The atomic number uniquely identifies a chemical element. read more