1. Atoms, Elements, and Molecules

2. Atoms Atoms are the building blocks of matter.
They make up everything that we know.
All matter is made of atoms.
Made up of three smaller parts.
Protons
Neutrons
Electrons

3. Atoms
Nucleus
8 Protons 8 Neutrons Oxygen

4. Atoms
Electrons
Atomic Shell

5. Elements Matter made of only one type of atom is called an element.
Element Name
Atomic Number
Element Symbol
Mass Number

6. Elements
Atomic Number: The number of protons in the nucleus of an atom.
Mass Number: The number of protons and neutrons in the nucleus.

7. Elements: Substances made entirely from one type of atom.

8. Molecules
A molecule is formed when two or more atoms join together chemically.
H2O Water
Molecular Oxygen O2
Methane
CH4

9. Which of these is NOT a compound
Compounds
Which of these is NOT
a compound
A compound is a molecule that contains at least two different elements.
All compounds are molecules not but not all molecules are compounds.
H2O Water
Methane
CH4
Molecular Oxygen O2

10. Challenge: Covalent Bonding
What you need to know:
The elements on the periodic table have the same number of protons and electrons.
Covalent bonds share electrons to fill an atoms valence shell.
Valence Shells
Holds the electrons of an atom.
Octet Rule: An atom is most stable when its outermost shell is filled with electrons.

11. Challenge
Number of electrons = 2n2
n = shell number

12. Challenge: CO2