1. Atomic Number Atomic Mass
Subatomic Particles
Atomic Number
Atomic Mass

3. Parts of the Atom Protons Neutrons Electrons
Positive charged particles found in nucleus
Neutrons
Neutrally charged particles found in the nucleus
Electrons
Negatively charged particles found outside nucleus

4. Atomic Number
The atomic number of an element is the number of protons in the nucleus.
The atomic number of an atom will never change.
If the number of protons in an atom changes, the atom no longer has the properties of that atom

5. Atomic Mass
The mass number is the total number of protons and neutrons in the nucleus.
That means that the mass number is the total number of protons plus the total number of neutrons.

6. Particles in an Atom
Using the atomic mass and atomic number the individual number of electrons, protons and neutrons can be calculated
mass number – atomic number = number of neutrons
(#Protons & #Neutrons) - (# protons) = # neutrons

7. Isotopes
An element having the same number of protons but different numbers of neutrons.
All atoms of an element have the same atomic number and therefore the same number of protons
Atoms of the same element but different numbers of neutrons are called Isotopes

8. Valence Electrons link
Valence Electrons are the outer most electrons that compose an atom
They determine bonding properties of the atom
Protons and Neutrons in the nucleus
Electrons in the electron cloud per orbital or levels
2 in the first level
8 in the second level
18 in 3rd level
32 in 4th level

9. Assignment
Atom Drawings worksheet