2. Compounds 2 broad categories: Ionic compounds Binary molecular compounds Both types of compounds: Composed of atoms in fixed ratios Atoms connected by chemical bonds
3. Bonds Bonds: Electrostatic attraction Holds atoms together 2 types: Ionic bond Occurs in ionic compounds Complete transfer of electron(s) from metal to non-metal Covalent bond Occurs in binary molecular compounds Sharing of electrons between two non-metals Formed in such a way that the octet rule for all atoms is satisfied Octet rule states that all atoms will have 0 or 8 electrons in their valence(outer) shell after a bond is formed
4. Application of Octet Rule Atoms with only 1, 2, or 3 valence electrons: Which groups? Tend to lose electrons Why? Examples(Grp. 1: Li, K, Na and Grp. 2: Be, Mg, Ca) Atoms with close to 8 electrons: Groups 6, and 7 Tend to gain electrons(why?) Examples(Grp. 6: O, S, Se and Grp. 7: F, Cl, Br, I)
5. Examples of Ionic Compounds Atom from Group 1 with an atom from Group 7 Li combining with F Li loses 1 electron Why? F gains 1 electron Why? Atom from Group 2 with an atom from Group 6 Mg combining with O Mg loses 2 electrons Why? O gains 2 electrons Why?
6. Example of an ionic compound: Li combining with F http://en.wikipedia.org/wiki/Image:Ionic_bonding.png)
7. Binary Molecular Compound Formed when 2 non-metals come together Formed via covalent bond Examples: CH4 CO2 SO3 N2O4
8. Example of a Binary Molecular Compound: Covalent Bond ({{Information |Description=Covalently bonded hydrogen and carbon in a molecule of methane. |Source=Created with Inkscape |Date=28 January 2006 |Author=DynaBlast |Permission=Creative Commons Attributio)
