Atomic mass
The number of neutrons in one atom can vary depending on the element. Neutrons are one of the three main subatomic particles found in an atom, along with protons and electrons. The number of neutrons in an atom is calculated by subtracting the number of protons (atomic number) from the atomic mass of the atom.
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.
The two subatomic particles you add together to get the mass number of an atom are protons and neutrons. Protons have a positive charge, while neutrons have no charge, but together they contribute to the mass of an atom.
Atoms are composed of neutrons, protons, and electrons. Neutrons and protons make up the nucleus of the atom, while electrons orbit around the nucleus in specific energy levels or shells. The number of protons in the nucleus determines the element of the atom.
There are 13 protons in an atom of aluminum, regardless of the isotope. If it didn't have 13 protons, it wouldn't be aluminum, it would be something else. There are 14 neutrons in an atom of aluminum 27, its only stable isotope.See the Related Questions for how to count the number of protons, neutrons and electrons in any atom of any element.
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.
Mass number!:)
protons and neutrons in an atom. It is the sum of protons and neutrons in the nucleus of an atom.
The mass number is the sum of protons + neutrons.
20. the mass of an atom is determined by the sum of the number of neutrons and protons the atom has.
The total amount of protons and neutrons in an atom is its mass number.
The number of protons and neutrons in the nucleus
Mass number = Protons+Neutrons
atomic mass number - protons = number or neutrons
The number of protons
The mass number of an atom is the sum of the protons and neutrons in its nucleus. Therefore, for an atom of calcium with 20 protons and 20 neutrons, the mass number would be 40.