history

Chemistry is the science that studies

Matter - anything that’s has a mass a weight and volume

A philosopher named Empedocles said matter was mad up of

4 elements

Democritus suggested matter was made up of tiny particles

Which could not be broken down any further

He called them

Atoms from the Greek word atomos meaning indivisible

Democritus was not accepted because

Socrates didn’t believe it was true

Aristotle believed the

4 elements theory

He came up with

Transmutation

The alchemist goals were

Change metal into gold , find the substance for eternal life

John dalton theory’s were

All elements are made up of atoms, atom are indestructible, atoms of the same element are exactly alike, two or more elements combine to form compounds , atoms are not created or destroyed in a chemical reaction

Dalton’s theory was

Billiard ball model, because he believed atoms were tiny spheres

J. J Thomson did this

He passed electricity through a gas and discovered negatively charged particles that he called electrons

He proved that atoms weren’t

Indivisible

Later he discovered

Positive particles that he called protons

He proposed that

Electrons have small mass and negative charge and the atom is a sphere of positive electricity

He’s said blank is stuck in blank

Electrons are stuck in the positive sphere

He called this the

Rasin bun theory

Ernest Rutherford did the

Gold foil experiment

He found that

He discovered a

Dense positively charged nucleus

He developed what we called the

Nuclear modle

Niels Bohr 1913 proposed that

Electrons orbit the nucleus like planets

He’s called this the

Planetary model

An atom is made of 3 subatomic particles

Protons electrons neutrons

Symbol and charge

Electrons take up the

Volume

An atom is a blank charge

Neutral

A nucleus has a

Positive charge

Protons and neutrons take up 99% of an atoms

Mass

Electron cloud is a

Is the area around the necleus basically the shells

Greeks did surface level

Experiments back in the day