What is atomic mass unit
Before we study the atomic mass unit, you should know about atoms. An atom is the smallest particle of an element that can't be further cut. In earlier ages, it was considered that the atom is the smallest element that cannot be divided further.
For example, when you cut an apple, cut it till it is cut able and at the last a stage come at which it would not be cuttable. That the smallest particle was called an atom. Atoms are combined together with a strong force and they form a molecule.
But later on, some more elements inside the atoms were discovered that were came to be known as electron, proton, and neutron. The electron carries a negative charge, the proton carries a positive charge while the neutron carries no charge. In the modern era, about 200 particles have been further discovered in an atom experimentally.
The atomic mass unit is a physical constant in the branch of science which is chemistry. It is one-twelfth of the mass of the carbon-12. It is a unit used for masses and expresses atomic mass and molecular mass.
The symbol used for this is amu.
1 amu in modern age= 1g/mol.
The atomic mass unit represents the sum of a number of protons and neutrons in a nucleus.
1amu=1.66 x 10^-27 kg
1amu=1.66 x 10^-24g
John Dalton was the first scientist to express the atomic mass unit in 1803. He suggested the use of protium(Hydrogen-1). Wilhelm Ostwald proposed that it would be better to express the mass of oxygen in 1/16. As hydrogen has three isotopes and oxygen has 4 isotopes so it varies. To avoid this confusion, in 1961, it was decided to use the Carbon-12 as the basic unit.