1. Chapter 5 ATOMIC STRUCTURE & CHEMICAL BONDING
CHEMISTRY
Chapter 5 ATOMIC STRUCTURE & CHEMICAL BONDING
Sec 1
WHY DO ATOMS COMBINE?

2. What we’ll learn?
Identify how electrons are arranged in an atom.
Compare the relative amounts of energy of electrons in an atom.

3. Why?
Chemical reaction takes place all around you!

4. Terms to know:
Electron cloud
Energy level
Electron dot diagram

6. Electron Cloud?
Area of space around the nucleus where electrons travel.
Electrons- (-ve) charge

7. Electron Arrangement:
Responsible for the physical & chemical properties of an element.

8. Energy Levels: Different areas of an electron in an atom.
Each energy level can hold the maximum number of electrons.
1st energy level- 2/1 e (electrons)
2nd e
3rd e
4th e
Formula:

9. Important: Electron closest to the nucleus- low amount of energy
farthest high amount of energy.

10. Electron Configuration (Bohr Model-1913)
HYDROGEN
LITHIUM

11. Stable: atoms w/ complete energy level Unstable: atoms w/ incomplete energy level.
BORON (unstable)
Noble Gases ( stable)

12. Halogen ( unstable)
Potassium (unstable)

13. Valence Electrons:
ELECTRONS that are in the outer level.

14. Electron Dot Diagram (Lewis Structure)
Electron dot diagrams, sometimes called Lewis dot diagrams.
Gilbert N. Lewis in 1916
Shows the reactive electrons of an atom found in the outer energy level important for chemical bonding.)