Valence Electrons ELECTRONS used in bonding (outermost)

Review – Ion Formation Cations – positive (+) charged Cations are created when a neutral atom LOSES electrons

Review – Ion Formation Anions – negative (-) charged Anions are formed when a neutral atom GAINS electrons

Chemical Bonding The cation (+) is always written first followed by the anion (-)

Monatomic Ions IONS consisting of only one atom Mg +2 Cl -1

Polyatomic Ions A group of elements that have an overall charge (NH4) +1 or NH4 +1 = Ammonium (PO 4 ) -3 or PO 4 -3 = Phosphate

Polyatomic Ions (find on ION Chart)

Chemical Bonding 3 main types of chemical bonding Metals or Nonmetals determines type

Color the PT the sub has like the following slide (colors don’t have to match) and then file it)

= METALS = NONMETALS

Bond #1 IONIC BOND bond formed between two ions by the transfer of electrons

Bond #1: Ionic Bond “Simplified” Opposite Charged Ions ‘Attract’ to each other

Bond #1: Ionic Bond METAL – NONMETAL (+) (-)

Sodium: Na +1 Chlorine: Cl -1 (cation) (anion) Na-Cl Notice the cation written 1 st (electrons are being transferred from Na to Cl to make the octet rule apply to both ions, everybody is happy)

Writing IONIC COMPOUNDS Get Handout showing how to write these compounds!!!!! This will help to COMPLETE #11 – 40 on Puzzle Piece Lab

1) Magnesium Chloride Mg +2

Cl -1

Mg +2 Cl -1 1 Mg piece 2 Cl pieces

All pieces must make a square/rectangle. No open ends. Keep adding both cations and anion pieces until you make a square/rectangle

Chemical formula for Magnesium Chloride Mg 1 Cl 2  MgCl 2

Stop here!!!!!!!!!!!!!!

Bond #2 Covalent Bond Nonmetal --- Nonmetal

Nitrogen N -3 Oxygen O -2 Can’t do the ‘flip and drop’ because they are the same charge, so they will share electrons!!! N 2 O (laughing gas or Nitrous)

When Nitrogen and Oxygen Combine they produce N2ON2O (laughing gas or Nitrous)

Covalent Bonds have a different naming system than Ionic See notes

Bond #3: Metallic Bond Metal – Metal (free flowing electrons)

Ionic Vs. Covalent Easy rule to decide if a covalent or ionic bond Ionic Bond = if any element in the compound is a metal (of any kind) it is automatically an IONIC BOND

Ionic vs. Covalent Covalent Bond = if the elements joined are all NON-METALS then it is a covalent bond

Periodic Table

Examples Aluminum Chloride AlCl 3 Ionic or Covalent?

Example Sulfur Dioxide SO 2 Ionic or Covalent

Watch OUT for Polyatomic ION Must check for polyatomic ions (both +/-) because some polyatomic ions have all nonmetals but have an overall + charge NH 4 Cl = Ammonium Chloride

NH 4 Cl Even though all elements in the compound are ‘non-metals’ the overall charge of the ammonium ion (polyatomic) is +1 and Chlorine is negative (Cl -1 ) Therefore, it is an IONIC bond because of attraction of opposite charges

Naming Ionic Compounds

Ionic Compounds Ionic Compounds = Compounds composed of positive and negative ions (ionic bond) Writing chemical names of ionic compounds

Naming: Few Simple Rules 1) Cations are always written 1 st  Monatomic cations, write element name just as it is on periodic table (Mg = Magnesium)  Polyatomic cations, only 1 we need to know = NH 4 = Ammonium

Naming Compounds 2) Anions are written 2 nd  Monatomic Anions: change the ending of the element name to “-ide” Chlorine to Chloride Fluorine to Fluoride Oxygen to Oxide Check to see if it sounds correct, is the only hint

Naming Compounds 2)  Polyatomic Anions: find their name on the ion sheet and write it accordingly CH 3 COO = Acetate CN = Cyanide Hint: If the second half of the compound has numerous elements, it is a polyatomic, so try to find it on ion sheet

Naming Do not worry about the small numbers of ionic compounds right now, we will address those later

Ionic Compound Naming MgCl 2 = Magnesium Chloride Ag 2 SO 4 = Silver Sulfate

Naming Molecular Compounds Nonmetal - Nonmetal B 2 H 6

Naming Covalent Compounds Different naming system than ionic compounds (metal-metal)

Covalent Compounds Only deal with 2 elements bonding together. (no poly)

B2H6B2H6

1st element Exactly like periodic table B 2 H 6 B = Boron

2nd element still has “- ide” ending B 2 H 6 H = Hydrogen = Hydride

We use Greek prefixes (on ion chart) to tell how much of each element we have B 2 H 6 2 Borons = Diboron 6 Hydrides = Hexahydride

B 2 H 6 2 Borons = Diboron 6 Hydrides = Hexahydride

B 2 H 6 Diboron Hexahydride

Mono - 1 ‘Mono’ is only used if the second element only has 1 atom We do not write ‘mono’ on 1st element written EVER CO = Carbon Monoxide (gas exhaust)

Name N 2 O

Write formula for Dinitrogen tetroxide

Example: N 2 O 4 Written without prefixes: Nitrogen Oxide Written with prefixes: Dinitrogen Tetroxide 2 = N 4 = O

**Drop the last vowel in a prefix if the starting letter of an element is the same vowel or if it sounds weird** TetraoxideTetroxide MonooxideMonoxide

This is why CO 2 what you are exhaling right now is called Carbon dioxide

** We don’t use ‘mono’ if there is only 1 atom of the first element, we only use it if the second element has only 1 atom*** Monocarbon Dioxide???? Carbon Dioxide CO = Carbon Monoxide