6.P.2.1 NOTESWhat are the smallest particles of

matter?What did Dalton conclude about atoms?

All elements are composed of extremely small particles called

atoms.

Atoms are the smallest particles of an element.

A molecule is a group of atoms that are joined

together and act as a single unit.

John Dalton proposed a new atomic theory that said all atoms had to have certain traits or

characteristics.

The 4 traits/ characteristics of Atoms according to John Dalton:

JOHN DALTON’S THEORY #1

Atoms cannot be broken into smaller pieces.

JOHN DALTON’S THEORY #2

In any element, all the atoms are exactly alike.

This explains why an element always has the

same properties.

JOHN DALTON’S THEORY #3

Atoms of two or more elements can combine to form compounds.

+ =

JOHN DALTON’S THEORY #4

Atoms of each element have a unique mass.

Exactly how small are atoms?

How many atoms do you think a sheet of paper

contains?

KEY CONCEPTS

1. All matter is made of atoms.

2. Different elements contain different atoms.

3. Everything is matter except energy.