1. Section 1 Structure of the atom and cells on the periodic table

2. Organization of The Periodic Table

3. Nucleus Center of the atom. Makes majority of the atom’s mass.
Made of Protons and Neutrons.
It vibrates
Nucleus

4. Protons
Part of the nucleus
Have positive (+) charge
Vibrate

5. Neutrons
Part of the nucleus
Have neutral charge
Vibrate

6. Electrons Orbit very quickly around the nucleus
Have negative (-) charge

7. Atomic Number Definition: the number of protons in the nucleus
Tells us the identity of the element.
Every element is defined by the number of protons in its nucleus

8. Isotopes
Atoms with the same number of protons but different numbers on neutrons
Example: Carbon
So you can change the number of neutrons and the element still maintains its identity

9. Atomic Weight
Calculate: the number of protons to the number of neutrons
Atomic Weight = # Protons + # Neutrons

10. Atomic Weight
But why is the atomic weight on the periodic table a decimal, shouldn’t it be a whole number?
The atomic weight on the periodic table is the average of all of the common isotopes of that element.
AVERAGE

11. Questions 1) What particles make up an atom?
2) What are the charges on these particles?
3) What particles make up the nucleus?

12. Questions 1) What is Oxygen’s atomic number?
2) How many protons does Oxygen have?
3) If I have 4 protons what element am I?
4) If I have 4 neutrons what element am I?