when you could check in most of atoms that we have you will see that the sum of protons and electrons equals to or is called the atomic weight or Atomic Mass...that is if you add protons to electrons you have your atomic mass.
The number of protons and electrons (in a neutral atom) is equal to the atomic number.
The sum hasn't a special meaning.
atomic number
it is called the atomic mass
Mass Number
Atomic mass is the total of the number of protons PLUS the number of neutrons.
The total amount of protons and neutrons in an atom is its mass number.
An atomic nucleus contain protons and neutrons; protons and neutrons contain quarks and gluons.
The number of protons
Depends on the atom. The atomic number will give you the number of protons. The atomic weight will give you approximately the number of protons and neutrons combined.
The pair below that describes isotopes of the same element is B, an atom with 6 protons and 6 neutrons-an atom with 6 protons. It is not A, an atom with 6 protons and 8 neutrons- an atom with 8 protons and 6 neutrons. Isotopes of the same element have the same number of protons and electrons, which is the atomic number of the element.
Atomic mass is the total of the number of protons PLUS the number of neutrons.
Atomic mass
nass number is the number of neutrons plus protons in the nucleus of an atom
The total amount of protons and neutrons in an atom is its mass number.
Mass number = Protons+Neutrons
An atomic nucleus contain protons and neutrons; protons and neutrons contain quarks and gluons.
The mass number is the sum of protons + neutrons.
The number of protons
Depends on the atom. The atomic number will give you the number of protons. The atomic weight will give you approximately the number of protons and neutrons combined.
To the find the mass number of an atom you add the protons and neutrons. Meaning that the mass number of this atom is 12.
The sum of the number of protons and neutrons in an atom