1. A visual representation of covalent compounds

2.  1. Octet Rule ◦ Covalent compounds share electrons so that each atom has an octet of electrons (8) in its highest energy level.  Exceptions:  Hydrogen has a full valence shell at 2 electrons  Boron has a full valence shell at 6 electrons instead of 8  2. Single Bonds ◦ 1 electron pair is shared (a total of 2 electrons)  3. Double Bonds ◦ 2 electron pairs are shared (a total of 4 electrons)  4. Triple Bonds ◦ 3 electron pairs are shared (a total of 6 electrons)

3.  Electron-dot notation can also be used to represent the structure of molecules, called Lewis Structures.  The pair of dots between the two symbols represents the shared electron pair of the hydrogen-hydrogen covalent bond.  In addition, each fluorine atom is surrounded by three pairs of electrons that are not shared in bonds.  An unshared pair, also called a lone pair, is a pair of electrons that is not involved in bonding and that belongs exclusively to one atom.

4. Step 1  Get a covalent formula and draw the electron-dot notation for each atom in the formula. Step 2  From the electron-dot notation, determine how many bonds each atom needs to get an octet.

5. Step 3  Determine the central atom (Skip this step if there are only 2 atoms): ◦ Carbon is always the central atom ◦ If there is more than 1 carbon they make a chain in the center.  -C-C-C- ◦ Hydrogen & group 17 elements are never in the center. ◦ The least electronegative is in the center. Step 4  Spread the remaining elements around the central atom & bond each to the center