Atomic mass unit | Definition, Description, Uses, & Facts
网页Atomic mass unit (AMU), in physics and chemistry, a unit for expressing masses of atoms, molecules, or subatomic particles. An atomic mass unit is equal to 1 12 the mass of a single atom of carbon-12, the most abundant isotope of carbon, or 1.660538921 × 10 −24 gram.
Atomic mass - Wikipedia
网页The atomic mass (m a or m) is the mass of an atom. Although the SI unit of mass is the kilogram (symbol: kg), atomic mass is often expressed in the non-SI unit dalton (symbol: Da) – equivalently, unified atomic mass unit (u). 1 Da is defined as 1 ⁄ 12 of the mass of a free carbon-12 atom at rest in its ground state. [1]
Dalton (unit) - Wikipedia
网页The dalton or unified atomic mass unit (symbols: Da or u) is a unit of mass defined as 1 / 12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest.
2.2: Atomic Number, Mass Number, and Atomic Mass Unit
网页The atomic mass unit (u or amu) is a relative unit based on a carbon-12 atom with six protons and six neutrons, which is assigned an exact value of 12 amu's (u's). This is the standard unit for atomic or molecular mass, and 1 amu is thus 1/12 th …
2.6: Atomic Masses - Chemistry LibreTexts
网页2024年1月15日 — The atomic mass is an average of an element’s atomic masses, weighted by the natural abundance of each isotope of that element. It is a weighted average because different isotopes have different masses. An atomic mass …
Atomic Mass Unit Definition (AMU) - ThoughtCo
网页2019年6月30日 — In chemistry, an atomic mass unit or AMU is a physical constant equal to one-twelfth of the mass of an unbound atom of carbon -12. It is a unit of mass used to express atomic masses and molecular masses.
Atomic mass | Definition, Units, & Facts | Britannica
网页Atomic mass, the quantity of matter contained in an atom of an element. It is expressed as a multiple of one-twelfth the mass of the carbon-12 atom, which is assigned an atomic mass of 12 units. In this scale, 1 atomic mass unit (amu) corresponds to 1.66 x 10^−24 gram.
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