The total number of protons and neutrons in a nucleus.
〔物理〕质量数
Example sentencesExamples
Different isotopes of the same element have different mass numbers because their nuclei contain different numbers of neutrons.
The mass number gives you the total number of protons and neutrons in the nucleus of that element.
The sum of the protons and neutrons is called the mass number.
Mathematical calculations employing the proportions and mass numbers have assigned titanium a mean atomic weight of 47.88.
Various numbers are used to define nuclei: the atomic number, Z, is the number of protons, while the mass number is the sum of the atomic number and the number of neutrons, N.
Definition of mass number in US English:
mass number
nounˈmæs ˌnəmbərˈmas ˌnəmbər
Physics
The total number of protons and neutrons in a nucleus.
〔物理〕质量数
Example sentencesExamples
The sum of the protons and neutrons is called the mass number.
Different isotopes of the same element have different mass numbers because their nuclei contain different numbers of neutrons.
The mass number gives you the total number of protons and neutrons in the nucleus of that element.
Various numbers are used to define nuclei: the atomic number, Z, is the number of protons, while the mass number is the sum of the atomic number and the number of neutrons, N.
Mathematical calculations employing the proportions and mass numbers have assigned titanium a mean atomic weight of 47.88.