Physical Science Unit 1

1. Physical ScienceUnit 1 Chapter 5 Lesson 3 Covalent Bonds

2. Start Up • Objectives: • Explain covalent bonds • Write electron-dot diagrams for simple molecules • Answer the following question: • How are molecules formed?

3. Covalent Bonds • A bond where valence electrons are shared between atoms • Enables atoms to form molecules

4. Diatomic Molecule • A molecule made up of two atoms of the same element • Electrons are shared equally • Only elements can have diatomic molecules: • Nitrogen • Oxygen • Hydrogen • Chlorine • Bromine • Iodine • Flouride

5. Hard to See! • Covalent bonds are hard to visualize, so scientists came up with a diagramming method to show these bonds • Called electron-dot diagram • A model in which the chemical symbol represents the nucleus and all the filled inner energy levels of the atom and one dot represents each valence electron

6. Let’s Do it! • Let’s do some electron dot diagrams together

7. Homework • Complete electron-dot ws in packet • Answer review questions