1. Counting Atoms The Chemistry of Life

2. Three Subatomic Particles: ChargeLocation Proton+1Nucleus Neutron0Nucleus Electron Electron cloud

3. Atomic Number The number of protons in an atom The number of protons in an atom Unique for every element Unique for every element

4. Atoms are always electrically neutral. This means that protons always equal the electron.

5. How many protons & electrons are in the following atoms? Silicon Silicon Nitrogen Nitrogen Zinc Zinc 14 p & 14 e 14 p & 14 e 7 p & 7 e 7 p & 7 e 30 p & 30 e 30 p & 30 e

6. Mass Number The number of protons and neutrons in the nucleus The number of protons and neutrons in the nucleus Mass Number – Atomic Number = Neutrons Mass Number – Atomic Number = Neutrons

7. How Many Neutrons are in: Potassium Potassium Argon Argon Tin Tin 20 n 20 n 22 n 22 n 69 n 69 n

8. Atomic Structure

9. Lithium

10. Phosphorus