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
Definition of Atomic Mass
Atoms are the basic units of matter. They are the smallest components of a chemical element, which is a substance that cannot be broken down into simpler material. Atoms have specific properties that will determine their chemical and physical nature. One of these properties is their atomic mass. This video will discuss atomic mass and its role in chemistry.
Atomic mass is roughly equal to the sum of the individual particle masses of an atom. Atoms have three basic components: protons (positively charged particles), neutrons (non-charged particles), and electrons (negatively charged particles).
Protons and neutrons are the larger particles, and are found in the nucleus, which is the core of the atom. Atomic mass is typically calculated by adding the number of protons and neutrons together, ignoring the electrons because of their small size. Daltons are the standard units used for measuring atomic mass.
Atomic mass units, or amu, are also used to measure atomic masses, and they are equal to daltons. The atomic mass of an atom will change depending on its amount of protons and neutrons, and will be different for each individual element.