Physics: Radioactivity and Atomic Structure

Radioactivity

Ionisation

An atom gains or loses an electron, the charges are no longer balanced and the charged atom is called an ion.

Excitation

When an atom absorbs electro-magnetic radiation and electron can move further from the nucleus.

De-excitation

If an electron moves closer to the nucleus then electro-magnetic radiation is emitted.

Isotopes

Different atomic form of the same element. Same number of protons as the element, but different number of neutrons.

Democritus

First person to come up with the idea of the atom. Indivisible.

Dalton

First gained scientific support that matter was made of atoms.

Thomson

Discovered the electron

Rutherford

Father of the nuclear age

Who proposed the plum pudding model?

JJ Thomson

What does the Plum Pudding Model suggest?

Atom was a ball of positive charge with negative particles distributed randomly within.