1. The Structure of the Atom

2. Protons and Neutrons Mass of proton:electron = 1836:1
Mass of neutron:electron = 1837:1
The ________________ has slightly more mass than the __________________.
Neutrons have no charge, so they neither attract nor repel protons due to ______________ _______________.
Strong Force
The force that causes neutrons and protons to attract each other.
Strongest force in nature
Overcomes the repulsion between _______________ charged protons.
Without strong force, atoms with more than one ___________________ would never form.

3. Standard Atomic Notation

4. Calculating the Number of Subatomic Particles
Atomic Number (Z) = ___________________________________________
Mass Number (A) = ___________________________________________
Number of Neutrons (N) = ___________________________________________
Number of Protons in a Neutral Atom = _________________________________

5. How to Draw Bohr-Rutherford Models
Draw a circle that represents the nucleus. Indicate the number of protons and neutrons. Use the symbols shown.
Determine the number of electrons in the atom. Draw the different energy levels using circles around the nucleus.
Maximum number of electrons:
First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 8
Forth Energy Level: 2 (for grade 9)
When filling the first energy level, place the first electron at 12 o’clock position. Add the next electron beside it. For the second energy level, begin at the 12 o’clock position, then 3 o’clock, then 6 o’clock, then 9 o’clock. If there are more than four electrons to be added, repeat this pattern.
Adding electrons to the third and forth energy levels is done in the same manner.