Section 3 ~ Covalent Bonds Chapter 5 Section 3 ~ Covalent Bonds

A. How Covalent Bonds Form Covalent Bonds form between atoms that share electrons. a. Usually occurs between nonmetals. b. A neutral group of atoms formed by covalent bonds is called a molecule.

2. How many bonds? Non metals can form single, double, and triple bonds (enough to fill their outer shell. Bond numbers are counted by the number of pairs shared between 2 atoms. Single Bonds

Double Bonds

Triple Bonds

3. Properties of molecular compounds: - lower melting and boiling points - do not conduct electricity when dissolved in water.

B. Unequal sharing of Electrons Atoms of some elements pull more strongly than do atoms of other elements. This causes the atoms to gain slight electrical charges. a. Not as strong as ionic charges. These are called polar bonds. ex. water

4. When the pull on the shared electrons is equal, this is called a nonpolar bond.

5. Attraction between polar molecules occurs because the positively charged ends attract the negatively charged ends. 6. Non polar molecules do not attract each other. 7. Polar compounds and nonpolar compounds do not mix because the polar molecules are attracting to each other. ex. water and oil.

8. Soap, you all should try it. J/K 8. Soap, you all should try it. J/K. Detergents have a nonpolar end and an ionic bond on the other end. The nonpolar end mixes with oil, dirt, and grease while the ionic end attracts the water. C17H35COONa