1
Dalton's Theory
Showed that atoms have (+) particles in the center, and are mostly empty space. Discovered in 1876.
Viewed atoms as tiny, solid balls, indivisible and indestructible particles, which have different masses and chemical properties. Discovered in 1808.
Has electrons moving around the nucleus in a cloud. Discovered in 1932.
2
Thomson's theory
Describes the atom as a positive sphere with scattered electrons, similar to a raisin bun. He suggested that electrons were embedded in a positive cloud, contributing to the understanding of atomic structure. Discovered in 1897.
Most of the atom's mass and positive charge is concentrated in a small, dense nucleus, while electrons orbit around it. Discovered in 1913.
3
Who discovered protons and nucleus?
Bohr
Rutherford
4
Who proposed the existence of energy levels or layers in atoms?
Chadwick, 1932
Bohr, 1913
5
Who discovered neutrons?
Chadwick
Democritus
6
Who proposed the atomic model with electronic orbitals?
Schrodinger
Democritus
