1. Starter CCl4 MgCl2 Guess at the names for these two compounds
Predict whether each is ionic or molecular compound

2. 6.b Chemical Names and Formulas
Unit 6 – Chemical Bonds
6.b Chemical Names and Formulas

3. Chemical Formulas molecular compound – covalently bonded
Nonmetal & nonmetal
number of atoms of each element contained in a single molecule of the compound
NO2, CH2Cl2,

4. Molecular Compounds
Learned this earlier this year – all nonmetals and involved the prefixes
Examples
PF5
phosphorus pentafluoride
XeF4
xenon tetrafluoride
dinitrogen pentoxide
N2O5

5. Chemical Formulas ionic compound – metal and nonmetal
represents one unit
simplest ratio of the compound’s anions and cations
MgO, Mg(OH)2, NH4Br

6. Monatomic Ions ions formed from a single atom
Not all elements easily form ions
Some atoms form covalent bonds instead
Others form ions without noble gas configurations
d and p-block metals
many form 2+ or 3+, some +1 or +4

7. Monatomic Ions
type of ion can be determined by looking at the number of valence e’s in the neutral atom
atom is more stable with a full shell
zero valence (losing e’s)
eight valence (gaining e’s)

8. Monatomic Ions cation anion positive if the atom loses electrons Be2+
Mg2+
Rb+
Al3+
Na+
anion
negative
if the atom gains electrons
N3- F-
S2-
O2-
Br-

9. Naming Monatomic Ions cations anions positive ion
written first in formula
by element’s name
add a Roman Numeral if it can form more than 1 type of ion
that is called the STOCK SYSTEM
anions
negative ion
written second in formula
by element’s root name + -ide ending

10. Binary Ionic Compounds
compounds made of two different ions
Crossing Over
write two ion types with correct charges
make the anion’s charge, the cation’s subscript
make the cation’s charge, the anion’s subscript
simplify the ratio if possible
combine the names of the two ions

11. Practice Naming Al and O Mg and Br Cu and Br Al3+ O2- Al2O3
aluminum oxide
Mg and Br
Mg2+ Br-
MgBr2
magnesium bromide
Cu and Br
Cu2+ Br-
CuBr2
copper (II) bromide OR
Cu1+ Br-
CuBr
copper (I) bromide

12. Practice Writing Formulas
iron (III) sulfide
Fe3+ S2-
Fe2S3
cadmium oxide
Cd2+ O2-
Cd2O2
CdO
potassium nitride
K+ N3-
K3N
tin (IV) sulfide
Sn4+ S2-
Sn2S4
SnS2

13. Compounds with Polyatomic Ions
the cation or anion could be a group of covalently bonded atoms instead of one atom
most polyatomic ions are oxyanions:
polyatomic ions containing oxygen
more than one polyatomic anion can exist for one element
sulfate ion: SO42- sulfite ion: SO32-

14. Practice Naming KNO3 NH4Br Cu(OH)2 CaSO4 potassium nitrate
from K1+ and NO3-
Cu(OH)2
copper (II) hydroxide
from Cu2+ and OH-
NH4Br
ammonium bromide
from NH41+ and Br-
CaSO4
calcium sulfate
from Ca2+ and SO42-

15. Practice Writing Formulas
sodium permanganate
Na1+ MnO4-
NaMnO4
iron (II) chlorite
Fe2+ ClO2-
Fe(ClO2)2
ammonium acetate
NH41+ CH3COO-
NH4CH3COO
calcium carbonate
Ca2+ CO32-
CaCO3