Matter Atomic Theory Notes Set 1
Jan 03, 2016
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.
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)
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).