1. Chapter 4.1 Atomic Theory

2. Atom Smallest particle of an element that has all the properties of that element Atomic theory is the study of the nature of atoms and how atoms combine to form all types of matter.

3. Atomic Theory Subatomic particles come together to form atoms Particles: 1. Protons – positive particles in the nucleus -charge is +1 -# protons = atomic # 2. Electrons – negative particles on orbits around the nucleus -charge is -1 -# electons = # protons= atomic # 3. Neutrons – neutral particles in the nucleus -charge is 0 -#neutrons= mass-atomic #

4. Structure of the Atom Electron orbit Valence shell Proton Neutron Electron

5. Bohr-Rutherford Diagrams Rules: 1. Calculate PEN 2. Write the number of protons and neutrons in the nucleus with the elemental symbol 3. Draw the number of electrons on orbits (2 on the first, 8 on the second, 8 on the third, unlimited on the fourth)

6. Draw the bohr diagram for Calcium

7. Draw the Bohr diagram for Oxygen

8. Lewis symbols A shorthand method of drawing representation of an element It shows the atomic symbol and valence electrons are draw surrounding the symbol Example: Calcium Oxygen

9. Homework Complete the Bohr diagrams for the first 20 elements