1. Writing Ionic and Molecular Compounds
Unit B - Chemistry
Writing Ionic and Molecular Compounds

2. 3.1 Naming Ions and Compunds

3. Ions
An ion is an atom or a group of atoms that has become electrically charged through the loss or gain of electrons.
Cation- positive charge
Anion- negative charge

4. Ions
Ions are elements with a charge- can be positive or negative charge
When a non-metal element has a charge its ending changes to become _________ide
Example: Chloride
Write out the differences between chlorine and chloride using the atomic symbol

5. On the Periodic Table What is the charge on the alkali metals?
What does that mean?
What is the charge on the alkaline earth metals?
What is the charge on the halogens?
What is the charge on the noble gases?

6. Drawing Diagrams Lithium Atom Lithium Ion Noble Gas
Chlorine Atom Chloride Ion Noble Gas

7. More Practice Magnesium atom Magnesium Ion Noble Gas
Oxygen Atom Oxide ion Noble Gas

8. I Can… Read and interpret chemical formulas
Use naming rules for elements, compounds and chemical reactions: use both IUPAC and common names

9. IUPAC International Union of Pure and Applied Chemistry
They are the body responsible for agreeing on the appropriate name for every chemical compound discovered

10. Chemical Formula
A chemical formula identifies which elements, and how much of each element are in the compound
What is a compound?
The chemical combination of two or more elements in a specific ratio
For example: CO2
Number of carbon atoms?
Number of oxygen atoms?
Number of total atoms?

11. Be careful with CAPITALS!
CO- carbon monoxide (1 carbon and 1 oxygen)
Co- cobalt, which is a transition metal
NOTE: every time we see another capital letter that tells us there is a new element

12. States of Matter
Another common notation added to a chemical compound indicates its state at room temperature.
We show states of matter using a subscript
Cu(S) –Indicates a solid
H2O(l) – indicates a liquid at room temperature
CH4(g) -indicates a gas

13. Multivalent Atoms
Many of the Transition Metals are Multivalent metals (more than one charge):
Sn2+
Sn4+
Fe2+
Fe3+

14. Polyatomic Ions
Polyatomic Ions are ions that contain more than one ion:
Why are Polyatomic Atoms named with –ATE/-ITE endings? To differentiate the number of oxygen atoms. Example PO4 -3is phosphate, PO3-3 is phosphite
NH4+
SO42-
MnO4-
Cr2O72-

15. To memorize Water (H2O) Ammonia (NH3) Methane (CH4) Table Salt (NaCl)
Sodium Hydroxide (NaOH)

16. 3.2 Ionic Compounds

17. I Can…
Distinguish between ionic and molecular compounds, and describe properties of each
Read and interpret chemical formulas
Identify and describe formulas for common household compounds
Build or draw simple ionic and molecular compounds
Identify ratios of atoms in common compounds and predict ratios of atoms in binary ionic compounds, using ionic charges
Represent familiar reactions, using word equations and chemical formulas

18. Introduction – Properties of Ionic Compounds
Ionic Compounds are all solid at room temperature
Many ionic compounds dissolve in water and becoming aqueous (liquid)
Ionic compounds in solutions conduct electricity

19. Structure Ionic Compounds are made of a metal ion and a non-metal ion
When ions are combined they form a crystal
Example: Table Salt

20. Structure in the Solution
Ionic compounds in solutions conduct electricity
When in a solution the ionic crystals will dissolve and the ions will float separately from one another
This allows conductivity: electrons (electricity) can move through the solution when there are ions.

21. Ionic Compound Conducting Electricity?

22. Ion Charges
To indicate ions in written notation, a plus sign (+) or a minus sign (-) is placed to the upper right of the element symbol element
For example NaCl would be written as Na+ and Cl-

23. How do the numbers work in a chemical formula?
Let’s think about it
How many electrons does a barium ion want to give away?
How many electrons does a chloride ion want?
So how many chlorides do we need for each barium?

24. Note: Ionic compounds want full electron shells- to do this they either have to give or take away electrons
IONIC COMPOUNDS ALWAYS FORM BETWEEN A METAL ION AND A NON-METAL IONS

25. Writing Formulas Write a metal ion and its charge
Write the non-metal ion and its charge on the same line
Add extra ions until the charges on each side balance
Write the formula with the number of each ion in subscript beside each symbol
Note: Ion charges are at the top, the number of ions are at the bottom

26. TRY: Calcium ion and oxide ion Sodium ion and iodide ion
Lithium ion and sulphide ion
Aluminum ion and selenium ion

27. Naming
For ionic compounds the metal ion is always named first- it doesn’t change its name
The non-metal ions goes second and it always changes its name to ____ide.

28. Practice Naming
Na2S(s)
BaL2(aq)
Ga2S3(aq)
CaO

29. The Periodic Table and Ion Charges
Take a look at the periodic table and look at the ion charge
Do you see a pattern?

30. Multivalent Bonds
If it is a multivalent metal we show the charge by using roman numerals 1=(1) 2=(II) 3=(III) 4= (IV) 5= (V)
It is written after the metal ion
Name Compounds
Gold (I) fluoride
Copper (II) oxide
Iron (II) sulphide

31. Practicing Naming
FeO
FeN
CuF2
Co2O3
HgS

32. What about the Box of Compounds?
If you look at your periodic table, you have polyatomic ions. They are groups of elements that have properties like ions.
When writing these in a compound, you will write them out the same way you see them written.
NaHCO3 – sodium bicarbonate (baking soda)
NH3OH – ammonium hydroxide

33. Practicing Naming
CaCO3
NH4NO3
Sn3(PO4)4
K2Cr2O7

34. To Do:
Naming Ionic Compounds Worksheet
Ionic Compound ID Assignment

35. 3.3 Molecular Compounds

36. I Can…
Distinguish between ionic and molecular compounds, and describe properties of each
Read and interpret chemical formulas
Identify and describe formulas for common household compounds
Build or draw simple ionic and molecular compounds
Represent familiar reactions, using word equations and chemical formulas

37. Introduction – Properties of Molecular Compunds
Molecular compounds are made from 2 or more non-metals
They can be solid, liquid, or a gas.
Molecular compounds are made of atoms
The atoms in a molecular compound share their electrons
Each atom fills its electrons by sharing electrons

38. Molecular Compound Conducting Electricity?
Molecular compounds do not conduct electricity.
Why?

39. Writing Formulas
Since there are no ions we don’t need to balance charges
We use a prefix to tell how many molecules there are
mono
Hepta di
Octa
tri
Nona
tetra
Deca
Penta
Hexa

40. Steps to Naming
Write down the name of the first element with its prefix
Write down the name of the second element using _____ide and its prefix
EXCEPTION- when the first element is 1 we do not use the mono prefix

41. Practice
CO2
N20
Dinitrogen trioxide
NF3
CCl4
Diselenium trioxide

42. Molecular or Ionic?
Molecular compounds have higher melting and boiling points that ionic compounds
Molecular compounds dissolved in water do not conduct electricity
Ionic compounds dissolved in water conduct electricity

43. Ionic Compound Conducting Electricity?

44. Molecular or Ionic?
H2O
CuCl2
NaCl
NH3
C12H22
BaSO4
Al2S3

45. To Do:
Naming Molecular Compounds Worksheet