Atomic models

John dalton

JJ Thompson

Ernest Rutherford

Neils Bohr

All matter is made up of small, indivisible particles called atoms

All atoms of an element are identical

Atoms of different elements have different properties

Thomson experimented with beams of particles produced in a vacuum tube and showed that the beams were made of negative charges.

Many different elements all produced the same type of beam, which suggested that all atoms have small, identical negatively charged particles

An atom is a positively charged sphere that have electrons embedded in them

Atoms are made up of smaller subatomic particles (made of protons and electrons) put together that make up the different elements

Rutherford directed positively charged particles at a sheet of gold foil.

He found that most particles went through the foil, providing evidence that the atom is mostly empty space.

Some particles bounced back, which provided evidence that there is a small, positively charged core in each atom.

Rutherford also experimented with masses of atoms and discovered the third subatomic particle, the neutron.

Atoms are mostly empty space

Atoms have a central core called the nucleus which contain protons and neutrons

Electrons move through the rest of the atoms space

Bohr observed that in a gas discharge tube, gases emit light when electrical energy is supplied to them.

By absorbing a specific quantity of energy, an electron could move to a higher energy level and by emitting the same quantity of energy, the electron could move back to its original energy level.

This provided evidence that electrons exist in specific energy levels surrounding the nucleus.

The nucleus has protons and neutrons

Electrons orbit the nucleus at specific energy levels/rings, called orbitals

The first orbital holds up to 2 electrons and all the other ones hold up to 8 electrons