The number of protons and neutrons in its' nucleus.
NEUTRONS AND PROTONS are counted in an atom to determine it's mass number.
mass number= no. of protons + no. of neutron
they determine the atomic mass of the atom
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The Number Of Protons & Neutrons In An Atom.
No. The mass number can be used, however, to determine the number of neutrons. Electrons can only be determined by knowing the atom's charge.
Number of Neutrons = Mass number - Atomic Number
the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
no --- atomic number
Essentially an atom's mass is determined by its number of protons and neutrons, as mass of electrons is so minuscule relative the nucleus.
To determine the number of protons, look at the atomic number. The number of electrons is also the atomic number.To find the number of neutrons subtract the atomic number from the Atomic Mass number.
protons plus neutrons