1. Valence Electrons and Bonding
Lesson 3.04
Valence Electrons and Bonding

2. Vocabulary Terms
Valence Electron- an electron of an atom, located in the outermost shell.
Bond – something that holds together.
Octet Rule/Rule of Eight - chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells.
Ionic Bonding - A chemical bond that results from electrostatic attraction between positive and negative ions. It is due to transfer of electrons between a metal and a nonmetal.

3. Vocabulary Terms
Covalent Bonding - A chemical bond in which electrons are shared between two atoms. The sharing of electrons between two nonmetals.
Electronegativity - tendency for an atom to attract a pair of electrons that it shares with another atom.
Polar Covalent Bond- a covalent bond where atoms have unequal attraction for the shared electrons.
Non-polar Covalent Bonds – a covalent bond in which the atoms have an equal attraction to the shared electrons.

4. Valence Electrons
Electrons in the outermost shell or highest energy level are called valence electrons.
Ex: Carbon – 1s2 2s2 2p2
Highest energy level is second level with four electrons(2s2, 2p2), therefore the number of valence electron for carbon is equal to 4.

5. Valence Electrons

6. Valence Electrons
Valence electrons = number of dots(Lewis Dot structure)

7. Ionic Bonding
Transfer of electron/s between a metal(+ion)
and a nonmetal(-ion)

8. Ionic Bonding
Ex: NaCl

9. Ionic Bonding – Let’s Practice
Mg + Cl
2) Al + O

10. Covalent Bonding
Sharing of electrons between 2 nonmetals(- ion)

11. Covalent Bonding Ex: CH4
Sharing of electrons between 4 atoms of Hydrogen
and 1 atom of carbon to form CH4.

12. Covalent Bonding- Let’s Practice
H + Cl
F + F

13. Polar Covalent Bond HF
F has a higher electronegativity than H, the atom with
greater electronegativity is able to take the electrons from
the other atom making it a negative ion and the other atom
as a positive ion. A Polar Covalent bond has an uneven
distribution of the charge, slightly negative on one end and
slightly positive on the other end.

14. Non Polar Covalent BondH2
2 atoms of Hydrogen having the same electronegativity.
Both atoms have the same strength of attraction for the
electrons and are equally shared. A Non polar covalent
Bond have an equal attraction for the shared electrons.