The number of protons is equal to atomic number.
Nucleon Number (total number of protons and neutrons)
The atomic number is the number of protons in an atom of an element.
Mass number is a value approximate to the number of protons (Atomic Number) plus the number of neutrons within an atom of the element considered. I say approximate as mass number takes into account the mass of the nucleus and not the actual number of protons and neutrons in the nucleus.
Mass number is the total number of protons and neutrons. because the nucleus consists of protons and neutrons only, the sum of protons and neutrons is the total number of ALL the nucleons. note the term "ALL" here.. this is the reason why mass number is denoted as "A".
The number of protons in a nucleus of an atom is called the "proton number", strangely enough. If you are a physicist, you will most likely prefer this term. Chemists however, would rather call it "atomic number".
The difference between proton number (which is atomic number) and nucleon number, which is the number of protons and neutrons in an atom's nucleus, is the number of neutrons in the nucleus of a given nuclide. Nucleons are the components of an atomic nucleus. We know that both protons and neutrons make up an atom's nucleus. So the number of nucleons, which is the number of protons and neutrons, minus the number of protons, will equal the number of neutrons in the atomic nucleus.
The number of protons in the nucleus is equal to the atomic number of that atom. Said another way, the atomic number of any element is the number of protons in the nucleus of any atom of that element.It might be helpful to consider some examples, and if we look at mercury, we'll see it has an atomic number of 80. All atoms of mercury have 80 protons in them. Aluminum has the atomic number of 13, so all atoms of it have 13 protons in them. Uranium, which has atomic number 92, has 92 protons in all of its atoms.The number of electrons and neutrons in a given atom of a given element can vary for a number of reasons, and these characteristics are considered separately. The number of electrons in any atom will match the number of protons in the nucleus of that atom only if the atom is a neutral one. Some atoms loan out or borrow electrons, and then they become what are called ions. The number of neutrons can vary, too, and we use the term isotope to talk about atoms of a given element having different neutron counts.The atomic number indicates the number of protons in an atom's nucleus.The number of protons in the nucleus is the atomic number of the atom.
It is the neutron that makes changes in atomic nuclei to change them from one isotope to another. For any given element, that element will have a fixed number of protons. It is, after all, the number of protons that determine the elemental identity. But the number of neutrons in a given element can vary, and we use the term isotope to talk about which particular atom we're investigating. That is, we apply the term isotope to speak to an atom of a given element with a certain number of neutrons in its nucleus.
In a neutral atom the protons and neutrons are equal; protons are determined by the element's atomic number. Therefore, the "neutron number" can refer to the atomic number- in a neutral atom only.
The nuclear charge is the term given to the electric charge on the nucleus, and it is simply found by counting the number of protons.
The atomic number of an element is determined by the number of protons in its nucleus. It's that simple. Note that the number of electrons will only equal the number of protons in an atom that is neutral, and can vary. The number of neutrons can vary as well, and we use the term isotope to differentiate between atoms of a given element with different numbers of neutrons in their nucleus.
NucleonsNucleons are subatomic particles, such as protons and neutrons, that exist in the nuclei (plural of nucleus) of atoms. Though a proton or neutron can exist outside the nucleus of an atom (though the neutron is unstable and will decay), either particle is considered a nucleon when we refer to them as the constituent parts of an atomic nucleus.Protons and neutrons reside in the NUCLEUS and are thus NUCLEONS. The probability of an electron being within a nucleus is quite small, so it is not considered a nucleon.