1. WRITING AND NAMING IONIC COMPOUNDS

2. When atoms combine, it’s always in simple whole number ratios
The smallest unit of atomic combinations that retains the characteristics of the compound is a molecule

3. The composition of a molecule can be represented in two ways as either an empirical formula or a molecular formula
CH2
C3H6
An empirical formula gives the simplest ratio of atoms in a compound
A molecular formula tells how many
of each atom
are present
in the compound

4. A remarkable feature of compounds formed from elements is that the properties of the reactant elements are lost. +

5. In order to become more stable an some atoms find it energetically fea-sible to either lose or gain valence electrons.
Atoms that lose e- are positive A.K.A. cation
Atoms that gain e- are negative
A.K.A. anion

6. We tend to focus specifically on the loss or gain of the outer s, p, (A.K.A. valence e-) ,and sometimes the d e- of unfilled d sublevels).
The valence e- an atom contains has a direct effect on the charge the atom develops as it forms an ionic bond.
We have a list of the common ionic charges developed during ionic bonding.

7. MONATOMIC IONS +1 SOME COMMON CATIONS
Lithium +1
SOME COMMON CATIONS
(Note: the names of many of the ions include Roman numerals These numerals are known as the Stock system of naming chemical ions and elements) +2 +3 +4
Li+1
Magnesium
Mg+2
Aluminum
Al+3
Lead (IV)
Pb+4
Sodium
Na+1
Calcium
Ca+2
Chromium(III)
Cr+3
Vanadium (IV)
V+4
Potassium
K+1
Strontium
Sr+2
Iron (III)
Fe+3
Tin (IV)
Sn+4
Rubidium
Rb+1
Barium
Ba+2
Vanadium (III)
V+3
Cesium
Cs+1
Cadmium
Cd+2
Copper (I)
Cu+1
Chromium (II)
Cr+2
Silver
Ag+1
Cobalt
Co+2
Copper (II)
Cu+2
Iron (II)
Fe+2

8. MONATOMIC IONS SOME COMMON CATIONS
(Note: the names of many of the ions include Roman numerals These numerals are known as the Stock system of naming chemical ions and elements) +1 +2 +3 +4
Lead (II)
Pb+2
Manganese (II)
Mn+2
MONATOMIC IONS
Mercury (II)
Hg+2
Nickel (II)
Ni+2
Tin (II)
Sn+2
Vanadium (II)
V+2
Zinc
Zn+2

9. MONATOMIC IONS SOME COMMON ANIONS
(Note: the names of many of the ions include Roman numerals These numerals are known as the Stock system of naming chemical ions and elements) -1 -2 -3 -4
MONATOMIC IONS
Fluoride
F-1
Oxide
O-2
Nitride
N-3
Chloride
Cl-1
Sulfide
S-2
Phosphide
P-3
Bromide
Br-1
Iodide
I-1

10. There are also combinations of covalently bonded atoms that also have a charge called polyatomic ions N H 4 +1 C O 3 -2 P O 4 -3 H O -1
Poly- means many, but we treat each of these polyatomic ions as a single unit with a single charge

11. +1 +2 -1 -2 -3 POLYATOMIC IONS Ammonium NH4+ Dimercury Hg2+2 Acetate
C2H3O2-
Carbonate
CO3-2
Phosphate
PO4-3
Bromate
BrO3-
Chromate
CrO4-2
Arsenate
AsO4-3
Chlorate
ClO3-
Dichromate
Cr2O7-2
Chlorite
ClO2-
Hydrogen Phosphate
HPO4-2
Cyanide
CN-
Oxalate
C2O4-2
Dihydrogen Phosphate
H2PO4-
Peroxide
O2-2
Hydrogen Carbonate
HCO3-
Sulfate
SO4-2
Hydrogen sulfate
HSO4-
Sulfite
SO3-2
Hydroxide
OH-
Hypochlorite
ClO-
POLYATOMIC IONS

12. -1 -2 -3 POLYATOMIC IONS Nitrate NO3- Nitrite NO2- Perchlorate ClO4-
Permanganate
MnO4-
POLYATOMIC IONS

13. Today is all about combining these electrically charged ions together to form stable compounds.
Reminder: when two atoms combine transferring valence electrons it is called an ionic bond.
Oppositely charged ions attract each other and form an ionic bond that is electrically neutral, to establish a molecule that is neutral.

14. Looking at the structure of salt shows that the attraction between ions is so great that many sodium ions and chloride ions become involved.

15. The results of each ion being surrounded by several other ions allows the attraction between oppositely charged ions to be much greater than the repulsion between ions with the same charge.
The strong attraction between the ions, & the orderly arrangement in the crystal affect the properties of the compound.

16. Cations & anions are pulled together in a tightly packed structure, giving each crystal a characteristic shape
The simplest repeating unit of anions and cations is called a unit cell.

17. Properties of ionic compounds
Can conduct electricity
When melted it frees up the ions to move past each other
Pack in highly ordered arrangements
Ions in a salt form repeating patterns called a crystal lattice

18. Properties of ionic compounds
Hard
Packed into layers, takes a lot of energy to break all of the bonds
Brittle
If a force is strong enough to reposition a layer then the repulsive forces drive ions apart

19. Properties of ionic compounds High melting points and boiling points
Because of strong attraction between ions, it takes a lot of energy to break them apart

20. Predicting the formation of ionic compounds.
We can predict the combinations of ions and the formation of their ionic formulas, knowing how ions interact
We can have 2 different kinds of ionic compounds formed: binary or ternary

21. WRITING IONIC FORMULAS
There are a couple of rules to follow to make sure that the proper ionic formula is written.

22. The sum of the ions’ charges must be zero
RULE #1
Ions will combine only in the simplest whole number ratio which cancels out the charge to form a neutral compound
The sum of the ions’ charges must be zero
3(+1) + (-3) = 0
+2 + (-2) = 0

23. It’s better to be positive than negative 
RULE #2
The compound formula is ALWAYS written with the cation first then the anion.
It’s better to be positive than negative 
NaCl
ClNa

24. Some ionic compounds’ charges automatically cancel each other out.K +1 + I -1 KI Mg +2 + O -2
MgO

25. How do we decide the proper ratio of cations and anions?
What if we were forming ionic compounds with ions whose charges don’t add up to a charge of 0?
How do we decide the proper ratio of cations and anions?

26. What if we had three chlorine ions for every one Aluminum ion?+3 + Cl -1 =2
What if we had three chlorine ions for every one Aluminum ion? Al +3 +
3 Cl -1
AlCl 3

27. We need to find the ratio Al +3
& O -2
We need to find the ratio
of ions that will make the charges cancel out to a neutral compound.
2 Al +3
&
3 O -2
Al O 3 2

28. IT’S NOT A TRICK SO MUCH AS A SHORTCUT!
We have a trick that will help us know the number of the ions to make a neutral compound.
IT’S NOT A TRICK SO MUCH AS A SHORTCUT!

29. CRISS-CROSS RULE: Al +3 + Cl -1
AlCl 3 Ca +2 + P -3 Ca 3 2 P

30. Using polyatomic ions
To write the formulas for compounds containing polyatomic ions, follow the rules for writing formulas for binary compounds, with one additional consideration.
We add parentheses around the polyatomic ion when more than one of the ion is needed to develop the proper ratio.

31. Al +3 + OH -1
Al(OH) 3 Na +1 4 + SO -2
Na SO 4 2

32. Practice Writing Formulas
Ca+2 & O-2 
Sn+4 & CO3-2 
NH4+1 & SO4-2 
Mg+2 & C2H3O2-1 
CaO
Sn(CO3)2
(NH4)2SO4
Mg(C2H3O2)2

33. NAMING THEM Most of the time you can name an ionic compound by
1) Writing the name of the first element
2) Writing the root of the name of the second element
3) Adding -ide to the root

34. Names of negative ions Parent element Negative ion Chlorine Chloride
Oxygen
Oxide
Nitrogen
Nitride
Phosphorus
Phosphide
Fluorine
Fluoride
Iodine
Iodide
Sulfur
Sulfide
Bromine
Bromide

35. CaCl2  K3P  Al2S3  NAMING THEM Calcium chloride Potassium phosphide
Aluminum sulfide

36. NAMING THEM Some of our metals have more than one ionic charge
We have to determine the charge on the metal
We then indicate the charge as a roman numeral

37. FeCl2  FeCl3  PbBr2  Iron(II) chloride Iron (III) chloride
NAMING THEM
FeCl2 
FeCl3 
PbBr2 
Iron(II) chloride
Iron (III) chloride
Lead (II) bromide

38. NAMING THEM If the compound has a polyatomic ion in it
1) name the first element, including the roman numeral if appropriate
2) then name the polyatomic ion

39. Fe(OH)2  Ca3 (PO4)2  Na2SO4  NAMING THEM Iron(II) hydroxide
Calcium phosphate
Sodium sulfate

40. Strontium Nitrite  Sr(NO2)2 CuOH  Copper (I) hydroxide
Lead (IV) phosphide 
Pb3P4
NH4OH 
Ammonium hydroxide
Sodium carbonate 
Na2CO3