An atomic mass unit (amu) and a Dalton are two different units used to measure the mass of atoms and molecules. However, they represent essentially the same quantity and can be used interchangeably.
The atomic mass unit (amu) is a unit of mass used to express the relative masses of atoms and molecules. It is defined as one-twelfth the mass of a carbon-12 atom, which is assigned a mass of exactly 12 atomic mass units. The amu is convenient for comparing the masses of different atoms or isotopes, as it provides a relative scale.
The Dalton (Da) is also a unit of mass used in the context of atomic and molecular masses. It is named after the British scientist John Dalton and is defined as the mass of one-twelfth of an unbound atom of carbon-12, which is equivalent to one atomic mass unit (amu). The Dalton is another term for the atomic mass unit, and the two units are considered interchangeable.
In summary, the atomic mass unit (amu) and the Dalton (Da) refer to the same unit of mass, representing one-twelfth the mass of a carbon-12 atom. They are used interchangeably to express the masses of atoms and molecules relative to this standard.