Wednesday 21 July 2021

ATOM - Theories & Models

Dalton Model

Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass

Thompson Model

Thomson proposed his model of the atom in 1903,then only electrons and protons were known to be present in the atom. According to Thomson Model of an atom, an atom consist of a sphere of positive charge with negatively charged electrons embedded in it

Rutherford Model

Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. He received the Nobel Prize in Chemistry in 1908

Bohr Model

The Bohr model shows that the electrons in atoms are in orbits of differing energy around the nucleus. Bohr used the term energy levels (or shells) to describe these orbits of differing energy. The energy level an electron normally occupies is called its ground state.

Electron Cloud Model

The electron cloud model tells us that we cannot know exactly where an electron is at any given time, but the electrons are more likely to be in specific areas.