1.2 discovery subatomic particles

What is Matter?

Anything with mass or takes up space

What is an Atom?

Smallest particle of matter that can exist by itself

Explain the term Molecule.

Group of atoms chemically joined

What are Ions?

Atom or group of atoms with a charge

State the Law of Conservation of Matter.

In chemical reaction, matter is neither created or destroyed

List the subatomic particles and their properties.

Protons, +1, Mass 1, Nucleus. Neutron, 0, Mass 1, Nucleus. Electron, -1, Mass 0, Orbiting Nucleus

What did Dalton discover?

Atomic Theory

What did Crookes discover?

Cathode Rays

What did Helmholtz discover?

Electricity made of particles

What did Thompson discover?

Electrons, Plum pudding model, Mass: charge ratio

What did Millikan discover?

Mass of e-, oil drop experiment

Mosley

Atomic Number, Number of protons

What did Bohr discover?

Energy levels, quantised

What did Rutherford discover?

Nucleus, Protons

What did Chadwick discover?

Neutrons

Explain Rutherford’s discovery of the nuclear atom.

Most pass through, so mainly empty space. Alpha particles, positive. Some deflected so positive centre. Some reflected( or bounced back ) so centre very dense.