1. Bonds…. Covalent Bonds Chapter 5 sec. 3 Mr. Sapalicio
Monterey Highland’s Elementary
Physical Science

2. How Covalent Bonds Form
Covalent bonds (shared valence electrons)- When 2 atoms share valence electrons.
COVALENT BONDS FORM BETWEEN UNCHARGED ATOMS.
Covalent bonds usually form between atoms of nonmetals
Nonmetals can bond to other nonmetals by sharing electrons
Most nonmetals can even bond with another atom of the same element
(ionic bonds form between metals and nonmetals.)

3. Electron Sharing
The force that holds atoms together in a covalent bond is the attraction of each atom’s nucleus for the shared pair of electrons.
Molecule- a neutral group of atoms joined by covalent bonds.

4. How many bonds?
Covalent bonds can be formed by as many atoms as necessary to complete the full 2/ 8 valence electrons shell.
Book p. 193 1 2

5. Single, Double, & Triple Bonds
The number of valence electrons an atoms needs will equal the number of covalent bonds it can form.

6. Single Bonds
Fluorine
Fluorine F F F F F2

7. Double Bonds When two atoms share two pairs of electrons. Ex: O2 CO2
Draw the electron dot diagram for both examples include the number of atoms listed in the subscript.

8. Water has 2 covalent bonds
H2O O H H
Water has 2 covalent bonds
H2O

9. Triple Bonds Atoms share three pairs of electrons.
Pg. 194 ex: Nitrogen N2
Draw the EDD for 2 nitrogen atoms.

10. H N H H
ammonia molecule
NH3

11. Question time????????
What is the difference between a double and a triple bond?
In a double bond, four electrons are shared, in a triple bond six electrons are shared.

12. Molecular Compounds
Pg. 63 review
Molecule- a neutral particle made of two or more atoms joined by covalent bonds.
Group of 2 or more atoms combined by chemical bonds.
Chemical bond- force of attraction between 2 atoms, hold atoms together. (BASIC)
A MOLECULAR COMPOUND is a compound that is composed of molecules. (COMPLEX)
The molecules of a molecular compound contain atoms that are covalently bonded.

13. Molecular compound
Compared to ionic compounds, molecular compounds generally have;
Lower melting and boiling points.
Unlike ionic compounds molecular compounds DO NOT conduct electric current when melted or dissolved.
BECAUSE- MC are made up of neutral molecules not ions so there is no charged particles.
They DO NOT break up into ions.
Examples of molecular compounds- plastic, water, rubber, table sugar.