Warm-Up 12/8/14 1) Get at least two different color utensils. 2) Draw the Lewis dot structures of the following elements: H, C, N, O, Cl 3) For each of the elements above, write down how many pairs of electrons there are and how many unpaired electrons there are.

Understand why atoms bond. Objectives Understand why atoms bond. Understand how many bonds a certain atom can make.

Free radicals and antioxidants Agenda Free radicals and antioxidants Covalent bonding

With unpaired electrons, atoms are very reactive. Why do atoms bond? With unpaired electrons, atoms are very reactive. Atoms with unpaired electrons are called radicals

Free Radicals and Antioxidants

Effects of Free Radicals

More are produced from stress, fatty foods, smoking, and drinking Where do they come from? Naturally occurring More are produced from stress, fatty foods, smoking, and drinking

Antioxidants

Help white blood cells destroy bacteria Free radicals are good too! Help white blood cells destroy bacteria

Then opposites attract! Ionic Bonding Recap Then opposites attract! Metal Nonmetal Loses electrons Gains electrons Becomes a cation (positive charge) Becomes an anion (negative charge)

Ionic Bonding Recap

Ionic Compounds Milk of Magnesia (Magnesium hydroxide – Mg(OH)2) Table Salt (NaCl – Sodium chloride) Pyrite (fool’s gold) (Iron (II) sulfide – FeS2) Chlorine bleach (Sodium hypochlorite – NaClO)

Covalent bond – bond made between two atoms by sharing electrons. Not everything is ionic though! Shared electrons Covalent bond – bond made between two atoms by sharing electrons.

How do we know how many electrons are available for bonding?

Bonding Like strangers at four park benches, each electron wants to sit alone first before sharing.

Bonding So oxygen has two pairs of electrons and two unpaired electrons. That means that oxygen can make two bonds.

Bonding Go back to the beginning How many bonds can each of those elements from the following make? H, C, N, O, Cl

Bonding Activity You are going to be drawing molecular models For each molecule, draw it inside your notebook with a color key.

Bonding Activity DO show paired electrons in the drawings. Only represent unpaired electrons with connecting lines. Have a color key!

Molecules you will be drawing: Bonding Activity Molecules you will be drawing: Water (H2O) Ammonia (NH3) Methane (CH4) Propane (C3H8) Carbon dioxide (CO2) Challenge! Laughing gas (N2O) Carbon monoxide (CO)

-Be like a covalent bond and share a piece of paper with a neighbor. Debrief -Be like a covalent bond and share a piece of paper with a neighbor. -Write what the difference is between ionic bonding and covalent bonding. Explain how the octet rule is followed in each.

Final Review Study Guide Homework Continue with Final Review Study Guide