Covalent Bonding and LDD 2018.notebook March 19, 2018 Covalent Bonds The electronegativity is difference small enough that valence electrons are shared Covalent Bonding to form a bond.

Covalent bonds have an E.N. difference between 0 and 1.7.

Aim: What are the properties of Covalent Bonds and NONPOLAR POLAR COVALENT BOND how do we draw covalent molecules? A bond between two A bond between two different identical nonmetal nonmetal atoms with different with equal electronegativity electronegativities SO SO electrons are shared equally. electrons are shared unequally.

Dec 1­4:53 PM Dec 1­5:12 PM

Covalent Bond Properties • Exist as individual molecules (NO CRYSTAL LATTICE).

• Solids are very soft and break apart easily. Triple Bond • Low melting and boiling points. 2e‐ shared 4e‐ shared 6e‐ shared

• Poor conductors because they WEAKEST STRONGEST do not contain charged particles that can become mobile (no ions or mobile electrons)

• Can form multiple bonds between atoms.

Dec 1­5:12 PM Mar 19­10:19 AM 1 Covalent Bonding and LDD 2018.notebook March 19, 2018

Drawing Covalent Lewis Structures e- bank Try drawing the for each molecule: 1. Determine the total number of valence e‐ 26e- for the molecule. (Sum of all valence electrons). 1. NF3 3. CO2

2. Arrange the atoms and put pairs of e‐ between them using single bonds. The least electronegative goes in the center (EXCEPT for hydrogen, H only gets 1 bond)

3. Distribute the remaining e‐ in pairs around the atoms to give each atom 8e‐. e- bank 2. N2 4. SO3 (Hydrogen only needs 2e‐) 12e-

4. Indicate the type of bond between atoms (polar covalent or nonpolar covalent)

5. If you can't make all atoms have octets, start over. Try a double or triple bond between two of the atoms until all atoms have full valence shells.

Dec 2­5:18 PM Dec 2­5:18 PM

Try drawing the Lewis structure for each molecule: Try drawing the Lewis structure for each molecule: 1. NF3 3. CO2

7. CCl4

2. N2 4. SO3

8. O2

Dec 2­5:18 PM Dec 2­5:18 PM 2 Covalent Bonding and LDD 2018.notebook March 19, 2018

1. Why does bonding allow an atom to become more Try drawing the Lewis structure for each molecule: stable?

2. How many total electrons are shared between the 7. CCl4 atoms in each molecule below? a. b. c.

8. O2 3. How many valence electrons does each atom have (including the shared electrons)?

4. List the molecules in order of weakest to strongest bond.

Dec 2­5:18 PM Dec 1­5:43 PM

3 Attachments

caramel­candy­recipe.jfif