1. Organization of The Periodic Table Open Chemical Building Blocks Book to Page 85. Get chalkboards, chalk, and eraser

2. Nucleus Center of the atom. Makes majority of the atom’s mass. Made of Protons and Neutrons. Nucleus

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

4. Neutrons Part of the nucleus Have neutral charge

5. Electrons Orbit around the nucleus Have negative (-) charge

6. 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

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

8. 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?

9. Reading the Periodic Table Mass

10. Atomic Mass Definition: the ~ mass of one atom of an element Tells us how much one atom weighs in atomic mass units. Mass

11. Subatomic Particles (Protons, Neutrons, and Electrons) The number of protons in an atom is called the atomic number. If you know the atomic number of an atom, you know how many protons – and how many electrons – the atom contains. # of protons = # of electrons (e - ) The mass number is the sum of protons and neutrons in the atom.

12. Assessment Which element has the greatest atomic mass? Lithium Sodium Potassium Rubidium

13. Question How many electrons does an oxygen have? How many electrons are in its outer shell? Which group is oxygen most likely to react with?