What is the modern

Jatomic theory?

The modern atomic theory has given by "John Dalton and framed postulates".

Explanation:

The fundamental role of atoms in chemistry is established by the modern theory of atoms mentioned in 1808 for the first time by an English scientist named John Dalton. This consists of three sections such as all matter is composed of atoms, atoms of the same element are the same while atoms of different elements are different, atoms combine to form compounds in full-number ratios.

The unique characteristic of the "number of protons" is that all atoms of the same compound share. While the atoms of the same element i. e having a similar number of protons can have different numbers of neutrons and such elements are called isotopes.