Question

State Dalton's atomic theory.

Answer 1

Hint: John Dalton FRS was a chemist, physicist, and meteorologist from England. He is best known for bringing the atomic principle into chemistry and for his colour blindness research, which is often referred to as Daltonism after him.

Complete answer:
Dalton's atomic theory:
In the year 1808, the English physicist and chemist John Dalton proposed Dalton's atomic theory, a mathematical theory on the origin of matter. It claimed that all matter is made up of atoms, which are small, indivisible particles.
The following are Dalton's atomic theory's postulates and limits.
Postulates:
Atoms are small, indivisible particles that make up all matter.
A single element's atoms have the same mass, size, and other properties. Atoms with different elements, on the other hand, have different properties and differ in mass and scale.
Atoms cannot be produced or destroyed in any way. Furthermore, atoms are incapable of being broken down into smaller particles.
Compounds are made up of atoms from various elements that mix in set whole-number ratios.
Chemical reactions allow atoms to be rearranged, joined, or isolated.
Limitations:
It doesn't take into consideration subatomic particles: Dalton's atomic theory claimed that atoms were indivisible. The discovery of subatomic particles such as protons, electrons, and neutrons, on the other hand, disproved this hypothesis.
Isotopes aren't taken into account: According to Dalton's atomic theory, all atoms of a given element have the same mass and density. Different isotopes of elements, on the other hand, have different atomic masses (Example: hydrogen, deuterium, and tritium).
Isobars aren't taken into account: According to this principle, the masses of atoms of two related elements must vary. It is possible, however, for two distinct elements to have the same mass number. Isobars are atoms that fall under this category.
Compounds do not have to be formed in simple whole-number ratios: Certain complex organic compounds don't have basic atom-to-atom ratios.
Allotropes are not taken into consideration by the theory: Dalton's atomic theory cannot justify the inconsistencies in the properties of diamond and graphite, which all contain only carbon.

Note:
The atomic theory of Dalton was the first attempt to explain all matter in terms of atoms and their properties. Dalton's philosophy was based on the laws of mass conservation and constant composition. All matter is made up of indivisible atoms, according to the first part of his theory. The theory's second section states that all atoms of a given substance have the same mass and properties. Compounds, according to the third section, are made up of two or three distinct groups of atoms. A chemical reaction, according to the fourth element of the principle, is an atom rearrangement. The discovery of subatomic particles and isotopes needed several changes to the theory.