Matter

Atomic TheoryNotes Set 1

How small can you go? Atoms- Elements- Molecules- Macromolecules- Cell organelles- Cells- Tissues- Organs- Systems- Organisms- Populations- Ecosystems- Biospheres- Planets- Planetary Systems with Stars- Galaxies- The Universe

Zooming out from atoms to universe

Why do we need to know about Atoms?

• Lithium used to make batteries…• Uranium is used in nuclear power plants• Carbon dioxide is a concern with climate

change• Hydrogen can power cars• Electricity is about electrons• Fuel of the future…• Understand everything….

Antiquity

• (400 B.C.) Democritus of northern Greece asserted that all material things are composed of extremely small irreducible particles called atoms.

Elements• One type of atom makes up an element.• There are approximately 100 elements each

with their own special properties.

The Elements

• All of the elements

Atoms

• The smallest division of an element. • If divided any smaller it stops retaining the

properties of that element.

• Bohr Atom Model

Atoms and the periodic table

• Proton has a positive charge +• Electron has a negative charge -• Neutron has no charge (0)

Draw an Atom

Reading the Periodic Table

• Atomic number = number of protons/ electrons

• Atomic Symbol = abbreviation of the name• Atomic Mass = number of protons plus/+

neutrons (electrons have very little mass)

Energy Levels

• Atoms have Electrons arranged into energy levels.

• Each level holds a certain amount of electrons.• The first holds 2 and the second holds 8 (you

will learn about the others later).

Periodic Table of the Elements

How to draw an Atom.

Draw an atom of Neon

Matter

Atomic TheoryNotes Set 1