1. Chemical Bonding and Nomenclature

2. Chemical Bond
Mutual electrical attraction between the nuclei and valence electrons of different atoms
Atoms bond to reduce potential energy
Atoms become more stable when they are bonded

3. Types of Chemical Bonds
Metallic – Attraction between metal atoms and the surrounding electrons
Ionic – Electrical attraction between cations and anions
Covalent – Sharing of electrons between atoms
Nonpolar Covalent – Electrons are shared equally between the atoms
Polar Covalent – Electrons are not shared equally between the atoms

4. Metallic Bonding
Empty d orbitals are overlapping – electrons flow between these empty orbitals creating a ‘sea of electrons’
A network of metal atoms forms in which the atoms attract the ‘sea of electrons’

5. Metals have Unique Properties
High electrical conductivity
Absorb and emit light – shiny
Malleable – can be hammered into thin sheets (Layers of atoms just slide past one another)
Ductile – can be drawn into a string

6. Ionic or Covalent???
Check the electronegativity difference between two atoms…
If the EN difference is greater than 1.7, the bond will be ionic.
If the EN difference is 0.3 to 1.7, the bond is polar covalent
If the EN difference is 0 to 0.3, the bond is nonpolar covalent

7. Ionic Bonding Cation transfers electrons to anion
Creates a crystalline solid – 3-D network of cations and anions
Lowest ratio of the cations to anions is represented by the formula unit

8. Formation of Ionic Compounds
Electron-dot notation – represents transfer of electrons

9. Example
Draw the electron dot diagram representing the formation of an ionic bond between
potassium and iodine
aluminum and oxygen

10. Characteristics of Ionic Bonds
Ions have strong attractions between them – this results in:
High melting point, high boiling point
Hard, but brittle
Layers of ions will break apart
Only electrical conductors in molten state
Many ionic compounds will dissolve in water

11. Things to know about ions before naming/writing ionic formulas
Cations can be monatomic or polyatomic ions
Monatomic charges are on the PT and polyatomic ions must be memorized (p. 210 of textbook)
Cations can also be transition metals – lose a varying amount of electrons – must use Roman numerals to indicate charge
Exceptions: Zn+2, Cd+2, Ag +1
Lead and Tin also use Roman numerals to indicate charge
Anions can be monatomic or polyatomic ions

12. Practice - Naming Ions Write the names the following ions: Ca+2 I-1
Cu+2
Zn+2
Pb +4
NO3-1
NH4+1

13. Answers
Calcium Ion
Iodide
Copper (II)
Zinc
Lead (IV)
Nitrate
Ammonium

14. Ionic Nomenclature To name an Ionic Compound Step 1: Name the cation
Check to see if it needs Roman numerals
Step 2: Name the anion

15. Examples NH4Cl NaBr CaI2 (NH4)2SO4 K2O Pb(ClO3)4 CuCl BaSO3 CuCl2 MnO
ZnBr2
K2SO4
Ca(NO3)2
NH4Cl
(NH4)2SO4
Pb(ClO3)4
BaSO3
MnO
AgCl

16. Answers Sodium bromide Calcium iodide Potassium oxide
Copper (I) chloride
Copper (II) chloride
Zinc bromide
Potassium sulfate
Calcium nitrate
Ammonium chloride
Ammonium sulfate
Lead (IV) chlorate
Barium sulfite
Manganese (II) oxide
Silver chloride

17. Writing Ionic Formulas
To write an ionic compound’s formula
Step 1: Write the formula for the cation – including charge
Step 2: Write the formula for the anion – including charge
Step 3: Balance the charges.
Be sure to use parenthesis if more than one polyatomic ion is needed

18. Examples Calcium chloride Barium sulfide Ammonium nitride
Iron (II) chloride
Lead (IV) sulfate
Barium phosphate
Calcium hydroxide
Iron (III) permanganate
Ammonium nitrite
Calcium carbonate
Copper (II) sulfate
Sodium acetate
Potassium sulfite
Sodium hydroxide

19. Acid Nomenclature The first element is Hydrogen – H____
To name an acid, look at the anion:
If the anion ends in –ide, change the name of the acid to hydro-ic acid
If the anion ends in –ite, change the name of the acid to –ous acid.
If the anion ends in –ate, change the name of the acid to –ic acid.

20. Examples
HCl
H2SO4
HClO3
HBr
H2S
HClO4
H2CO3
HNO2

21. Answers Hydrochloric acid Sulfuric acid Chloric acid Hydrobromic acid
Hydrosulfuric acid
Perchloric acid
Carbonic acid
Nitrous acid

22. Acids – Writing Formulas
To write the formula for an acid
Step 1: Decide which ion is needed based on the ending
Step 2: Add H+1 in front of the anion
Step 3: Balance the charges

23. Examples Hydroiodic acid Phosphorous acid Sulfurous acid Nitric acid
Acetic acid
Phosphoric acid
Hypochlorous acid

24. Answers HI
H3PO3
H2SO3
HNO3
HCH3COO or CH3COOH
H3PO4
HClO