Asked by: Bettye Polainosasked in category: General Last Updated: 7th February, 2020
What is the definition of mass number in chemistry?
Just so, what is a mass number in chemistry?
The mass number (symbol A, from the German word Atomgewicht [atomic weight]), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. The mass number is different for each different isotope of a chemical element.
Likewise, what is atomic number and mass number in chemistry? The number of protons determines an element's atomic number and is used to distinguish one element from another. Together, the number of protons and the number of neutrons determine an element's mass number.
People also ask, what is mass number example?
The total number of protons and neutrons in the nucleus of an atom. For example, nitrogen has 7 protons and 7 neutrons in its nucleus, giving it a mass number of 14. Isotopes of elements are distinguished by their mass number; for example, carbon-12 and carbon-14 have mass numbers of 12 and 14 respectively.
How do you find the mass number?
The atomic mass equals the number of protons plus the number of neutrons, so you find the number of neutrons by subtracting the number of protons (i.e. the atomic number) from the atomic mass (in atomic mass units).