Covalent and Metallic Bonding 6 1 Covalent Bonds

Covalent and Metallic Bonding 6. 1

Covalent Bonds �In Covalent Bonding – Atoms share electrons. So instead of atoms forming ions to have a complete outer shell, they can also share electrons to achieve a full outer shell.

Covalent Bonds �In covalent bonding, both atoms want the electrons. The space that these shared electrons move into is called a molecular orbital. �Page 191 in the book has a visual of a molecular orbital.

Covalent Bonds �Covalent bonding occurs between nonmetals (and metalloids) on the right side of the table.

Metallic Bonds �Metallic bonds are the result of sharing of valence electrons of each metal atom with all of the other atoms in the solid metal. �The electrons can move easily from one atom to another. This gives metals its ability to conduct.

Metallic Bonds �In metallic bonds, electrons are delocalized. This means that they do not stay attached to one atom. The reason for this is that metals do not want to keep their electrons, they would rather lose. The metal atoms move electrons from atom to atom like a “hot potato. ” Another phrase used to describe metallic bonding: “a sea of electrons. ”

Back to Covalent Bonding: Molecular Orbitals and Dipoles �A molecular orbital is made when two atomic orbitals overlap. �A molecule that has one positive end and one negative end is called a dipole. This results from unequal sharing of electrons.

Covalent Bonds �There are 2 different kinds of covalent bonds: . Polar Covalent 2. Nonpolar Covalent 1

Polar Covalent Bond �Polar Covalent Bonds are when the 2 atoms share the electrons unequally. Example: Carbon and Oxygen – Oxygen wants electrons more than Carbon, so the electrons will be closer to Oxygen. Example: H 2 O

Nonpolar Covalent Bond �Nonpolar Covalent Bonds is a bond in which the atoms share the electrons equally or almost equally. �Example: O 2

Nonpolar Covalent Bonds �Diatomic molecules share electrons equally. They are 2 of the same atoms bonded together. Know all 7. �I 2, Br 2, Cl 2, F 2, O 2, N 2, H 2 �They make the number 7 on the Periodic Table.

Determine type of Bond �Turn to page 194 in the book. You can predict what type of bond is formed from subtracting electronegativity values from each other. Nonpolar Covalent : 0 – 0. 5 Polar Covalent: 0. 51 – 2. 1 Ionic: larger than 2. 1

Determine type of Bond �Calculate Electronegativity differences between the 2 atoms and determine the bond: - Nonpolar Covalent, Polar Covalent, or Ionic � 1. C and Cl � 2. Al and F � 3. S and P � 4. C and N 5. Na and Cl