1. Lime emits a bright light when heated to a high temperature
Lime emits a bright light when heated to a high temperature. Limelight was used to produce a light that could be focused on a single spot on a stage. The flowerpots seen here were coated with a solution of lime and water.
Two or more names for a compound can be confusing. Chemists use a single system for naming compounds.

2. Describing Ionic Compounds
What information do the name and formula of an ionic compound provide?
The name of an ionic compound must distinguish the compound from other ionic compounds containing the same elements. The formula of an ionic compound describes the ratio of the ions in the compound.

3. Describing Ionic Compounds
These objects are coated with compounds of copper and oxygen. Based on the two colors of the coatings, copper and oxygen must form at least two compounds. There must be at least two names to distinguish red copper oxide from black copper oxide.

4. Describing Ionic Compounds
Notes
Binary Ionic Compounds
- compound made from only 2 elements
The names have a predictable pattern:
the name of the cation
followed by the name of the anion

5. Describing Ionic Compounds
This table lists eight common anions. The name of an anion is formed by adding the suffix –ide to the stem of the name of the nonmetal.

6. Notes
Transition metals
- will give electrons from last level
- will also give electrons from next to last level
- possible to have more than 1 oxidation #

7. Describing Ionic Compounds
Metals With Multiple Ions
Many transition metals form more than one type of ion. Many paint pigments contain compounds of transition metals.

8. Describing Ionic Compounds
The table shows a copper(I) ion with a 1+ charge and a copper(II) ion with a 2+ charge.
These ion names can distinguish red copper(I) oxide from black copper(II) oxide.
The formula for “copper one oxide” is Cu2O because it takes two Cu1+ ions to balance the charge on an O2– ion.
The formula for “copper two oxide” is CuO because it takes only one Cu2+ ion to balance the charge on an O2– ion.

9. Writing Formulas for Ionic Compounds
Notes
Writing Formulas for Ionic Compounds
The symbol of the cation is first, followed by the symbol of the anion.
Compound must have a neutral charge.
Use subscripts to show the ratio of the ions in the compound.

10. a. Iron (II) Oxide Fe +2 O -2
FeO
Fe2O2
FeO

11. b. Copper (II) Chloride Cu +2 Cl -1 Cl -1
CuCl2

12. c. Aluminum Sulfide Al +3 Al +3 S -2 S -2 S -2
Al2S3

13. Writing Formulas for Ionic Compounds
Notes
Writing Formulas for Ionic Compounds
The symbol of the cation is first, followed by the symbol of the anion.
Compound must have a neutral charge.
Use subscripts to show the ratio of the ions in the compound.
Parentheses are used with the subscript for polyatomic ions. The formula for iron (III) hydroxide is Fe(OH)3

14. Describing Ionic Compounds
Polyatomic Ions
This electron dot diagram models a group of atoms that includes one nitrogen atom and four hydrogen atoms.
The ammonium ion loses a valence electron as it forms. This loss leaves only 10 electrons to balance the charge on 11 protons, so the ion has a positive charge.

15. Notes
polyatomic ion
covalently bonded group of atoms that has a positive or
negative charge
acts as an atom
most are anions

16. a. Lead (II) Nitrate Pb +2
NO3 -1
NO3 -1
PbNO2
Pb (NO3)2

17. b. Calcium Hydroxide Ca +2 OH -1 OH -1
CaOH2
Ca(OH)2

18. c. Calcium Phosphate Ca +2 Ca +2 Ca +2
PO4 -3
PO4 -3
Ca3(PO4)2

19. Describing Ionic Compounds
4. What is the name of the compound whose formula is NaOH?

20. Describing Ionic Compounds
4. What is the name of the compound whose formula is NaOH?
Answer: In the formula, Na represents the sodium ion, and OH represents the hydroxide ion. The name of the compound is sodium hydroxide.

21. Describing Molecular Compounds
Naming Molecular Compounds
The general rule is that the most metallic element appears first in the name. These elements are farther to the left in the periodic table.
If both elements are in the same group, the more metallic element is closer to the bottom of the group.
The name of the second element is changed to end in the suffix -ide, as in carbon dioxide.

22. Describing Molecular Compounds
There may be more than one molecular compound that can exist with the same two elements.
The Greek prefixes in the table are used to name molecular compounds.
The prefix octa-means “eight,” as in the eight tentacles of an octopus.

23. Describing Molecular Compounds
Two compounds that contain nitrogen and oxygen have the formulas N2O4 and NO2.
The name of the compound with the formula N2O4 is dinitrogen tetraoxide.
The name for the compound with the formula NO2 is mononitrogen dioxide. The prefix mono- often is not used for the first element in the name, so a more common name is nitrogen dioxide.

24. Describing Molecular Compounds
Writing Molecular Formulas
To write the formula for a molecular compound, write the symbols for the elements in the order the elements appear in the name.
The prefixes indicate the number of atoms of each element in the molecule.
The prefixes appear as subscripts in the formulas.
If there is no prefix for an element in the name, there is only one atom of that element in the molecule.

25. Describing Molecular Compounds
What is the formula for diphosphorus tetrafluoride?

26. Describing Molecular Compounds
What is the formula for diphosphorus tetrafluoride?
Because the compound is molecular, look for elements on the right side of the periodic table.

27. Describing Molecular Compounds
What is the formula for diphosphorus tetrafluoride?
Because the compound is molecular, look for elements on the right side of the periodic table.
Phosphorus has the symbol P. Fluorine has the symbol F.

28. Describing Molecular Compounds
What is the formula for diphosphorus tetrafluoride?
Because the compound is molecular, look for elements on the right side of the periodic table.
Phosphorus has the symbol P. Fluorine has the symbol F.
Di- indicates two phosphorus atoms, and tetra- indicates four fluorine atoms.

29. Describing Molecular Compounds
What is the formula for diphosphorus tetrafluoride?
Because the compound is molecular, look for elements on the right side of the periodic table.
Phosphorus has the symbol P. Fluorine has the symbol F.
Di- indicates two phosphorus atoms, and tetra- indicates four fluorine atoms.
The formula for the compound is P2F4.

30. Which of these formulas describes a binary ionic compound?
Assessment Questions
Which of these formulas describes a binary ionic compound? O2
MgCl2
NO2
Fe(OH)3

31. Which of these formulas describes a binary ionic compound?
Assessment Questions
Which of these formulas describes a binary ionic compound? O2
MgCl2
NO2
Fe(OH)3 ANS: B

32. What is the correct name for CCl4?
Assessment Questions
What is the correct name for CCl4?
carbon(IV) chloride
carbon tetrachlorine
carbon tetrachloride
monocarbon tetrachloride

33. What is the correct name for CCl4?
Assessment Questions
What is the correct name for CCl4?
carbon(IV) chloride
carbon tetrachlorine
carbon tetrachloride
monocarbon tetrachloride ANS: C