Elements

Elements make up everything we see in our world

Sand can be cut into an infinite number of smaller and smaller pieces

Aristotle

Actually, sand is made of atoms which make up all material things. Atoms are indivisible.

Democritus

Elements are made of atoms. Atoms of a given element are identical in size, mass and properties. They cannot be divided, created, or destroyed.

John Dalton

Ernest Rutherford

ATOMIC STRUCTURE

The positive charge of the atom and most of its mass is concentrated in the middle of the atom called the nucleus

Elements are made of atoms  of only one kind that cannot be broken down into simpler chemical substances

An atom consists of three types of subatomic particles

The subatomic particles carry charges:

There are 118 elements, each with its own chemical properties

Each has its own name and symbol

They are organized by atomic number and property on the periodic table