1. Chemical Bonding

2. Chemical Bonds / Formulas
Atoms bond to become “happy” – octet rule
When they bond they form compounds.
Each compound has a special formula
Subscripts show how many of each element is in the compound

3. FORMULAS MgCl2 The subscript is the number at the bottom of a formula.
There is 1- Mg & 2 – Cl
Never use 1 as a subscript!

4. IONIC BOND formed between two ions by the transfer of electrons

5. Formation of Ions from Metals
Ionic compounds result when metals react with nonmetals
Metals lose electrons to form a positive charge
Nonmetals gain electrons to form a negative charge
Metals: Nonmetals:
Na+ N -3
Ca+2 S -2
Al+2 Br -

7. IONIC BONDS Bonds form from the (+) & (-) charges.
Form a network of ions. Form strong bonds.
Conduct electricity when melted or dissolved in water.

9. Writing Ionic Formulas – binary
Magnesium & chlorine Write the metal ion Mg +2 Write the nonmetal ion Cl - If charges DO NOT cancel – drop & swap MgCl2
Calcium & oxygen Write the metal ion Ca +2 Write the nonmetal ion O -2 If charges cancel – ratio is 1:1 ( 1 of each) CaO

10. Transition Metals – d & f block
Ion charges change – an element can have more than one ion charge
The charge is given as a ROMAN NUMERAL
Ex: Iron (II) Fe+2 / Iron (III) Fe+3
Gold (I) Au + / Gold (III) Au+3
You will not have to memorize all the charges each transition metal forms – the charges will be given to you !!!!!

11. Practice Magnesium & iodine Iron (III) & bromine Barium & nitrogen
Aluminum & phosphorus

12. Naming Ionic Formula - binary
Transition Metals
Name the metal & Include the charge using a Roman Numeral
Change the ending of the nonmetal ending to –ide
Ex:
Fe Cl iron (II) chloride
Au + O gold (I) oxide
Representative Metals
Name the metal
Change the ending of the nonmetal to – ide
Ex:
MgCl magnesium chloride
AlP - aluminum phosphide

13. Practice
FeCl3
Ni3N
ZnO
FeS
CaBr2
Na3N
BCl3
MgO

14. Ternary Ionic Bonds – contain Polyatomic Ions
Polyatomic ion : a group of (covalently) bonded nonmetals that form a charge.
Act as a single ion in an ionic bond
Have special names that DO NOT CHANGE
You need to write down the polyatomic ions and their names on an index card and DO NOT LOSE IT!!!
You will use your list on all quizzes and tests!

15. Ammonium NH4+
Acetate C2H3O2-
Hypochlorite ClO-
Chlorite ClO2-
Chlorate ClO3-
Perchlorate ClO4-
Cyanide CN-
Hydroxide OH-
Nitrite NO2-
Nitrate NO3-
Bicarbonate/Hydrogen Carbonate HCO3-
Carbonate CO3-2
Chromate CrO4-2
Dichromate Cr2O7-2
Oxalate C2O4-2
Sulfate SO4-2
Sulfite SO3-2
Phosphite PO3-3
Phosphate PO4-3
Permanganate MnO4-
Peroxide O2-2

16. Writing Ionic Formulas - ternary
Write the cation – all metals (only polyatomic cation is ammonium: NH4+ )
Write the anion – all nonmetals and polyatomic ions
If charges cancel – 1:1 ratio
If charges DO NOT cancel – drop & swap
You must use parenthesis if more than one polyatomic ion is present

17. Naming Ionic Formulas- ternary
Cation
Representative metals- element name
Transition (D-block) metals- element name and a Roman numeral to show charge
Polyatomic ion (NH4+)- regular name
Anion
Polyatomic ion- regular name
Nonmetal- change ending to -ide
Ex:
NaNO3- sodium nitrate
Cu2(SO4)3- copper (III) sulfate
NH4Cl- ammonium chloride

18. Practice Iron(III) chlorite cesium nitrate Zinc(II) nitrite
Gold(III) carbonate
Silver(I) phosphite
Copper(I) acetate
cesium nitrate
barium sulfite
aluminum hydroxide
strontium phosphate
ammonium sulfide

19. COVALENT BOND bond formed by the sharing of electrons

20. Covalent compounds result when nonmetals bond with nonmetals
Both nonmetals share their valence electrons to be happy – Octet Rule
Examples:
CO2 SCl2
H2O CH4

21. Naming Covalent formulas
Use prefixes to show the # of atoms of each element in a covalent compound
1 – mono hexa
2 – di hepta
3 – tri octa
4 – tetra nona
5 – penta 10 – deca
1st element – use prefixes only of the # of atoms is greater than 1
2nd element – use prefixes; change ending to – ide

22. Practice carbon dioxide trinitrogen octafluoride
CO2
N3F8
Se4Br9
S7O
carbon dioxide
trinitrogen octafluoride
tetraselenium nonabromide
heptasulfur monoxide

24. Writing Covalent formulas
Use the prefix to identify how many of each nonmetal atoms are in each molecule
The prefix becomes the subscript.
Carbon Tetrahydride Disulfur Hexachloride
CH4 S2Cl6

25. 1) Name the following covalent compounds:
a) SiF4
b) N2S3
c) H3Br7
d) S5Br9
e) H2O
Write the formulas for the following covalent
compounds:
a) diboron hexahydride
b) nitrogen tribromide
c) sulfur hexachloride
d) diphosphorus pentoxide

26. Drawing Structures- Ionic
Electrons are TRANSFERRED
Practice:
NaBr
AlCl3

27. Drawing Structures- Covalent
Electrons are SHARED
1 pair= single bond
2 pairs= double bond
3 pairs= triple bond
Dot formulas and Structural formulas

28. Covalent Structure Practice
H2O CH4
CO2 Cl2
O2 N2

29. Diatomic Molecules H2, N2, O2, F2, Cl2, Br2, I2
Always pair up with themselves in a pure sample
Allows them to be stable when there are no other elements to bond with
H2, N2, O2, F2, Cl2, Br2, I2

30. Metallic Bonds Formed between two metals
One or two valence electrons (usually transition metals)
strong positive nuclei pull atoms close together, causing the outer e- orbitals to overlap
electrons delocalize; creates a ‘sea of electrons’
electrons flow freely between atoms, this is why metals are good conductors of electricity

31. The remaining slides are for HONORS CHEMISTRY only

32. VSEPR Valence Shell Electron Pair Repulsion
Predicts shapes of covalently bonded molecules
Copy the chart on p.263 of your book

33. Coordinate Covalent Bonds
one atom contributes both bonding electrons
once formed, no different from other bonds, just different source of electrons

34. Coordinate Covalent Ex:
Chlorate, ClO3-

35. Resonance Structures
shifting of electron pairs/bonds without shifting atoms

36. Resonance Ex:
Carbonate, CO3-2
Ozone, O3