Bonding

1. What two types of bonds form and how do they form?

Chemical Bonds This is the force of attraction between two elements. Bonds involve valence electrons. Valence electrons: Electrons in the outermost energy level of an atom. Atoms react (form bonds) to have a stable octet (noble gas structure).

Covalent Bonds A covalent bond is formed when valence electrons are shared by both atoms.

Covalent Bonds Covalent bonds are between nonmetals and nonmetals.

Covalent Bonds A pair of shared electrons forms a single bond.

Covalent Bonds Both atoms become stable (octet) due to the covalent bonding.

Ionic Bonds: Ionic Bonds are formed by the attraction of equal and opposite charges.

Electrons are transferred in an ionic bond. Ionic Bonds Electrons are transferred in an ionic bond.

Ionic Bonds

Ionic Bonds – Electrostatic Attraction

Ions Atoms that have a positive or negative charge.

Metals – Cations (+) Nonmetals – Anions (-) Metalloids Periodic Table

Ionic Bonds occur between: A metal (cation) and a nonmetal (anion) A metal (cation) and a negative polyatomic ion A positive polyatomic ion and a nonmetal (anion) A positive polyatomic ion and a negative polyatomic ion

Cations – Positive Ions Cations are ions formed by metals that are positively charged due to the loss of an electron.

Cations – Positive Ions Cations have low ionization energy. They lose electrons easily to become positive.

Anions – Negative Ions Anions are nonmetals that are negatively charged due to the gain of an electron.

Anions – Negative Ions Non-metals have high electronegativity. They gain electrons to become negative and form anions.

POLYATOMIC IONS Polyatomic ions are mostly made of two (or more) non-metals. They stay together – Treat as one ion. Ions with -1 charge perbromate BrO4-1 bromate BrO3-1 bromite BrO2-1 hypobromite BrO-1 perchlorate ClO4-1 chlorate ClO3-1 chlorite ClO2-1 hypochlorite ClO-1 periodate IO4-1 iodate IO3-1 iodite IO2-1 hypoiodite IO-1 nitrate NO3-1 nitrite NO2-1 hydroxide OH-1 cyanide CN-1 acetate C2H3O2-1 Permanganate MnO4-1 bicarbonate HCO3-1 Ions with a -2 Charge carbonate CO3-2 sulfate SO4-2 sulfite SO3-2 chromate CrO4-2 dichromate Cr2O7-2 oxalate C2O4-2 Ions with a -3 Charge phosphate PO4-3 phosphite PO3-3 arsenate AsO4-3 Ions with +1 charge ammonium ion NH4+1

Oxidation Number Group Oxidation Number 1A 1+ 2A 2+ 3A 3+ 4A 4+/4- 5A 3- 6A 2- 7A 1- The charge on an ion. positive (cation) negative (anion) Predicted by the group/family (column).

Ionic Bonds The bone represents an electron. The dog that takes the bone is negative. The dog that loses the bone is positive.

Ionic Bonds - Review Electrons are transferred from a metal to a nonmetal. Metals give up electrons to form cations; Non-metals take electrons to form anions The attractive forces bring the cation and anion together. Both achieve an octet of electrons.

Ionic Bonds Quiz 1) In an ionic bond, electrons are _____. 2) The type of electrons involved are ___ or outer shell electrons. 3) Metals ___ electrons, nonmetals ___ electrons in order to get a ___ gas configuration (stable octet). 4) Cations have a __ charge and are formed by __. 5) Anions have a __ charge and are formed by __. 6) ____ charges hold the compound together.

2. How are ionic compounds formed?

3. How are ionic compounds named?

Naming Binary Ionic Compounds The cation (+ ion) is written first, followed by the anion (- ion). Atoms combine so that they are neutral. Name 1st element as is (cation). Name 2nd element (anion) using the “ide” ending. What is the name of AlBr3? Aluminum bromide

Practice Naming Ionic Compounds 1) NaCl Sodium chloride 2) MgF2 Magnesium fluoride 3) Al2O3 Aluminum oxide 4) CaS Calcium sulfide 5) GaP Gallium phosphide 6) K2O Potassium oxide

NAMING TERNARY Ionic COMPOUNDS (POLYATOMIC IONS) 1) Name cation (+) ion. 2) Name the polyatomic ion as a group. (ate, ite) Ex. CaSO4 cation=calcium anion=sulfate Name: Calcium Sulfate

Practice: Name the Compound 1) NaClO3 sodium chlorate 2) AlPO4 aluminum phosphate 3) (NH4)2S ammonium sulfide 5) CaCl2 calcium chloride

Writing Formulas for Ionic Compounds The oxidation numbers have to add up to zero. Determine oxidation numbers of the ions. Cations – Look at Periodic Table. Anions – Look at the Periodic Table or Polyatomic Ion chart. Balance the charges by adding subscripts. Put polyatomic ions in parenthesis if there is more than one.

Writing Formulas for Ionic Compounds Write the formula for calcium chloride. Calcium is Ca2+ Chloride is Cl1- Ca2+ Cl1- would have a 1+ charge. Need another Cl1- Ca2+ Cl21-

Crisscross Switch the numerical value of the charges Ba2+ N3- 2 3 Ba3 N2 Reduce ratio if possible

Crisscross

Practice Writing Ionic Formulas Aluminum Bromide cation anion Al3+ Br- AlBr3 Sodium Oxide Na+ O2- Na2O

Stock System Nomenclature Some metals can form more than 1 charge. Determine the (+) charge to make the compound neutral. Use Roman Numeral (in parentheses) to show the (+) charge. Ex. CuCl = Copper ( ) chloride Cl = -1 so Cu must be +1 to be neutral. (I) Name = copper (I) chloride

Stock System Nomenclature SnO Tin ( ) oxide Since oxide = 2- then Sn must be 2+ = 0 Tin (II) oxide FeCl3 Iron ( ) chloride Since chloride = 1- x 3 = -3 Fe = +3 = 0 Iron (III) chloride

Stock System Formulas 1) copper (I) sulfide Cu+ S2- Cu2S 2) copper (II) sulfide Cu2+ S2- CuS 3) iron (III) oxide Fe3+ O2- Fe2O3

Name the Compounds * Use Stock System* 1) * CuCl Cl = -1 Cu = +1 Copper (I) chloride 2) * CuCl Cl = -1 x 2 = -2 Copper (II) chloride 3) * PbS Lead (II) sulfide S = -2 Pb = +2 4) * PbS2 Lead (IV) sulfide S = -2 x 2 = -4 Pb=+4 5) * FeBr3 Br = -1 x 3 = -3 Fe=+3 Iron (III) bromide 6) AgI Ag has only 1 ion, +1 Silver iodide

4. What is unique about ionic compounds that have Hydrogen as a cation?

Acids

Acids Ionic compounds that have Hydrogen (H+) acting as a cation are called acids. Formulas usually begin with ‘H’. HCl HNO3 H2SO4 HClO3 H3BO3 *CH3COOH

5. How are acids named?

Acid Nomenclature Flowchart

How to Name Binary Acids: hydro_________ic acid. Example: HCl - Hydrochloric Acid Example: HF - Hydrofluoric Acid

How to Name Tertiary Acids: Tertiary acids ending in –ate: ___________ ic acid Tertiary acids ending in –ite: ___________ous acid An easy way to remember which goes with which… “In the cafeteria, you ATE something ICky”

How to Name Tertiary Acids: Examples H2SO4 sulfuric acid HNO2 nitrous acid

6. How are covalent compounds formed?

7. What are the two types of covalent compounds that can be formed based on the way electrons are shared?

2 Types of Covalent bonds 1. Polar Covalent: Electrons are shared unequally. 2. Nonpolar Covalent Electrons are shared equally.

Polar Covalent Molecules Unevenly matched but willing to share Stronger dog gets a larger portion of the bone Element that’s more electronegative pulls the pair of electrons towards it.

Polar Covalent Molecules Due to the uneven sharing of electrons, there is a more positive end and more negative end to the molecule. This causes polar covalent molecules to interact with other polar covalent molecules and ionic compounds.

Polar Covalent Molecules Electronegativity is the reason for the unequal sharing of electrons. Some atoms have a stronger attraction for electrons.

Nonpolar Covalent Molecules Dogs of equal strength Both dogs have equal attraction for the bone

Nonpolar Covalent Molecules There are no partial charges. Nonpolar Covalent Molecules only dissolve in other nonpolar covalent molecules.

8. How are covalent compounds named?

Naming Covalent Compounds Number of atoms (subscript) Prefix 1 mono- 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa- 9 nona- 10 deca-

Covalent Bond Naming Rules Use Prefixes to indicate the number of atoms of each element (Look at the subscripts). Add the suffix “–ide” to the ending of the name of the last element. Remember that “mono” is not used for the first element, only subsequent elements.

Binary Covalent Compound Naming Practice = carbon dioxide CO = carbon monoxide SO2 SO3 P2O5 NO BH3

Covalent Compounds with “Common Names” Chemical Name H2O Water NH3 Ammonia N2H4 Hydrazine N2O Nitrous Acid (Laughing Gas)

Choose covalent (2 nonmetals) or ionic (metal+nonmetal or polyatomic) Choose covalent (2 nonmetals) or ionic (metal+nonmetal or polyatomic). Determine Names. KCl NO NaNO3 NH4Cl SO3 CBr4

Mixed Review Name the following compounds: 1. CaO 2. SnCl4 a) calcium oxide b) calcium(I) oxide c) calcium (II) oxide 2. SnCl4 a) tin tetrachloride b) tin(II) chloride c) tin(IV) chloride 3. N2O3 a) nitrogen oxide b) dinitrogen trioxide c) nitrogen trioxide

Mixed Review Dinitrogen monoxide Potassium sulfide Copper (II) nitrate Dichlorine heptoxide Chromium (III) sulfate Iron (III) sulfite Calcium oxide Barium carbonate Iodine monochloride

9. What are organic compounds and how are they named?

Bonding The End