1. Elements, Atoms, Molecules & Compounds

2. Elements An element is a simple substance that cannot be broken down
Ex: Iron, Mercury, Oxygen
More than 100 elements
Can be solid, liquid or gas at room temp. (most are solid)
Iron = Solid
Mercury = Liquid
Oxygen = Gas

3. Periodic Table of Elements

4. Atoms
An atom is the smallest part of an element that can be recognized as the element *****
Made up of three particles:
Neutrons: neutral charge (0)
Protons: positive charge (+)
Electrons: negative charge (-)
Atoms have no overall charge because each one has the same number of protons and electrons
Atoms are too small to see with our eyes
Millions of atoms could fit on the period at the end of this sentence.

5. Protons and neutrons are found in the center, or nucleus, of the atom
Electrons are spread out around the nucleus in locations called “shells” or “energy levels”
The electrons found in the outermost shell are called valence electrons
Each shell can hold a specific number of electrons (2, 8, 18, 32, 32, 18, 8)

6. How many protons are there? Neutrons? Electrons?
An Example of an Atom + + + +
How many protons are there? Neutrons? Electrons?

7. Molecules
A molecule is at least two atoms that are bonded (stuck) together
Can be the same or different elements
Think of it as a string of atoms

8. Compounds
A substance that is made of two or more elements bonded together
Must have at least two elements
Ex: Water (H2O)
Oxygen
Hydrogen

9. Water is actually a molecule and a compound.
It is made of at least two atoms bonded together.
Those atoms are made of two different elements.
Oxygen
Hydrogen

10. Matter Atoms make up matter Matter makes up EVERYTHING
Matter is anything that has mass and volume
Examples include:
The planet Earth
You
Your pen
A rubber band