Dalton's Atomic Model

In 1808, John Dalton proposed the first scientific model of the atom. According to him, atoms were the fundamental building blocks of matter. He described atoms as tiny, solid, indivisible spheres that combine to form compounds.

Main Postulates of Dalton’s Atomic Theory:

1. Matter is made of small indivisible particles called atoms.
2. All atoms of a given element are identical in mass and properties.
3. Atoms of different elements have different masses and properties.
4. Atoms combine in fixed whole-number ratios to form compounds.
5. In a chemical reaction, atoms are neither created nor destroyed but exchange partners to give new substances.

Thus, Dalton’s atomic theory suggested that atom is indivisible. But the discovery of sub-atomic particles like electron, led to a revision of this theory.