1. Ionic Bonding and Nomenclature

2. Quick Review: Parts of the Periodic Table
Noble gases
Alkali metals
Transition metals
Halogens
Alkaline-earth metals
Lanthanides
Actinides

3. Quick Review: Parts of the Periodic Table

4. Quick Review: Parts of the Periodic Table

5. What is an ion?
Ions are atoms that carry either a positive or negative charge. Cations are positively charged. Anions are negatively charged.

6. How to remember which is which:
Think of the “t” in cation as a plus sign!
ca ion

7. How are ions formed? Part 1
Remember that an atom of any element ALWAYS has the same number of protons. (If the number of protons changed, then you would have a different element!!)
Remember that neutral atoms (atoms that are NOT ions) have EQUAL numbers of electrons and protons
This means that the positive and negative charges CANCEL OUT!

8. How are ions formed? Part 2
In order for an ion to be negatively charged (meaning it is an anion), there must be more electrons than protons
The number of protons can’t change, so how can there be more electrons than protons?
The atom must gain an electron in order to have more electrons than protons!

9. How are ions formed? Part 3
In order for an ion to be positively charged (meaning it is a cation), there must be more protons than electrons
The number of protons can’t change, so how can there be more protons than electrons?
The atom must lose an electron in order to have fewer electrons than protons!

10. Picture It: Anions
A Hydrogen atom has 1 proton and 1 electron. This means Hydrogen has 1 positively charged particle and 1 negatively charged particle.
Hydrogen can form a hydride ion, which has a -1 charge. This means that
It has one more electron than proton
The number of protons can’t change
So it must have gained an electron

11. Picture It: Anions
A Hydrogen atom has 1 proton and 1 electron. This means Hydrogen has 1 positively charged particle and 1 negatively charged particle.
Hydrogen can form a hydride ion, which has a -1 charge. This means that
It has one more electron than proton
The number of protons can’t change
So it must have gained an electron

12. Picture It: Cations
A Lithium atom has 3 protons and 3 electrons. This means Lithium has 3 positively charged particles and 3 negatively charged ones.
Lithium ions have a +1 charge. This means that
They have one more proton than electron
The number of protons can’t change
So it must have lost an electron

13. Picture It: Cations
A Lithium atom has 3 protons and 3 electrons. This means Lithium has 3 positively charged particles and 3 negatively charged ones.
Lithium ions have a +1 charge. This means that
It has one more proton than electron
The number of protons can’t change
So it must have lost an electron

14. Notation
When writing an ion, you write the symbol of the element, followed by a superscript of the element’s charge. It doesn’t matter if you write the + and – signs before or after the number. If the number of the charge is 1, you can write just the + or – sign.

15. Notation Ca2+ OR Ca+2 F- OR F-1 OR F1- Examples:
Calcium forms an ion with a positive 2 charge. You can write its symbol as either:
Ca2+ OR Ca+2
Fluorine forms an ion with a negative 1 charge. You can write its symbol as any of the following:
F- OR F-1 OR F1-

16. How do you know what kind of ion forms?
Remember: Noble gases are the most stable elements—they don’t really react with anything. This is because they have full valence shells (their outermost shell of electrons is full). In actuality, ANY atom will be stable if it can get a full valence shell.

17. How do you know what kind of ion forms?
To determine how many electrons an atom will gain or lose, figure out what would be the easiest way for it to have the same number of electrons as the closest noble gas on the periodic table.

18. The Octet Rule
As a general rule, atoms are most stable with eight valence electrons. This is called the Octet Rule.
Note that this is not always true! But MOST of the time it works.
When deciding what kind of ion an atom will form, ask yourself if it would be easier for the element to lose all of its valence electrons or gain enough to have eight total.

19. Practice Time With the Periodic Table
Ex: Would it be easier for Sodium to lose one valence electron to look like Neon, or gain seven electrons to look like Argon?

20. Practice Time With the Periodic Table
It would be easier for Sodium to lose one electron and form the Na+ ion.

21. Practice Time With the Periodic Table
With a partner, come up with five other examples. Pick five elements and determine what ions they will form to get a full octet. See if you notice a pattern!

22. Yes, of course there’s a shortcut
The representative elements all have a specific charge associated with them that depends on which group they’re in. +1 +2 +3 -3 -2 -1
MULTIPLE POSSIBILITIES! We’ll worry about these later.

23. Practice
Predict what charge would be on an ion made out of each of the following elements. Rb S Al F Ba P

24. Practice
Predict what charge would be on an ion made out of each of the following elements.
Rb+
S2-
Al3+
F-1
Ba+2
P-3

25. Ionic Bonds
What happens when two magnets of the same type get near each other?
They repel!
Magnetism is sometimes caused by electricity—moving charged particles.
So what will happen when two ions of the same charge get near each other?
They will repel!

26. Ionic Bonds
What happens when two magnets of the OPPOSITE type get near each other?
They attract!
So what will happen when two ions of the opposite charge get near each other?
They will attract!

27. Ionic Bonds An ionic bond is formed when:
Two atoms get near each other, and
One donates an electron to the other (meaning one will lose an electron and the other will gain that same electron) and the atoms become ions.
The two ions now have an opposite charge and are attracted to each other.
They stick together!

28. Ionic Bond Example
Na Cl
[Na]+ [ Cl ]-
[Na]+[ Cl ]-

29. Ionic Bond Formation Practice
Try drawing the formation of an ionic bond between Ca and F. Hint: You may need more than one atom of one of the elements!

30. Ionic Bond Formation Practice
Try drawing the formation of an ionic bond between Ca and F.
Ca F F

31. Ionic Bond Formation Practice
Try drawing the formation of an ionic bond between Ca and F.
F Ca F

32. Ionic Compounds
When two ions bond together, they form an ionic compound.
You can recognize an ionic compound because it will contain
An ion of one type of METAL
An ion of at least one type of NONMETAL

33. Practice
Tell whether the compound is ionic or not. Remember, an ionic compound will have ONE METAL and AT LEAST ONE NONMETAL.
NaCl
CO2
K2O
Mg3(PO4)2
SiO4
NH3

34. Practice
Tell whether the compound is ionic or not. Remember, an ionic compound will have AT LEAST METAL and AT LEAST ONE NONMETAL.
NaCl
CO2
K2O
Mg3(PO4)2
SiO4
NH3
Ionic
Not

35. Nomenclature
Nomenclature is a fancy-sounding word that just means a system of naming. Ionic compounds have a special set of nomenclature rules. If you know the formula of an ionic compound, you can follow the rules to write the compound’s name. Let’s try it with CaCl2.

36. Step 1: Write the NAME of the Cation (Metal)
All metals ions have positive charges
Therefore all metal ions are cations
What is the cation (metal) in CaCl2?
Calcium
So you just write the word “Calcium.”
This step never changes! You can always at least do this part.

37. Step 2: Determine the anion
The cation (metal) has to be paired with an anion.
If the anion is one single type of element, the compound is BINARY.
If the anion is multiple elements, the compound contains a POLYATOMIC ION—an ion made up of multiple types of atoms.
We’ll come back to these.

38. Practice 1. Binary 2. Polyatomic 3. Binary 4. Polyatomic 5. Polyatomic
Tell if the compound is a binary atomic compound or if it contains a polyatomic ion.
K2S
Mg2OH
SrBr2
Al(ClO3)3
CsSO4
1. Binary
2. Polyatomic
3. Binary
4. Polyatomic
5. Polyatomic

39. Step 3a: Binary Ionic Compounds
Look at the periodic table to figure out the name of the anion element.
In CaCl2, the anion element is chlorine.
Change the end of the element name to end in “—ide.”
“Chlorine” becomes “chloride.”
So the full name of CaCl2 is “Calcium chloride.”

40. A Quick Note
When you change the ending of an element to “—ide,” you should change them certain ways.
Anything ending in “—ine,” just change “—ine” to “—ide”
The other main ones change like this:
Oxygen ---> oxide
Sulfur---> sulfide
Phosphorous ---> phosphide
Nitrogen ---> nitride

41. Practice Strontium bromide Potassium sulfide Sodium chloride
Name the following binary ionic compounds.
SrBr2
K2S
NaCl
Rb2O
Li3P
Strontium bromide
Potassium sulfide
Sodium chloride
Rubidium oxide
Lithium phosphide

42. Step 3b: Compounds with Polyatomic Ions
Find the chart of polyatomic ions on your STAAR Reference Sheet.

43. Step 3b continued
Find the name of the polyatomic ion you’re looking for on the chart.
Write the name of the polyatomic ion next to the name of the metal.
You’re done!

44. Practice
Name the following ionic compounds containing polyatomic ions.
SrSO4
Al(OH)3
Na3PO4
Ca(NO2)2
Now for some tricky ones…
5. NH4ClO
6. NH4F

45. Practice Strontium sulfate Aluminum hydroxide Sodium phosphate
Name the following ionic compounds containing polyatomic ions.
SrSO4
Al(OH)3
Na3PO4
Ca(NO2)2
Now for some tricky ones…
5. NH4ClO
6. NH4F
Strontium sulfate
Aluminum hydroxide
Sodium phosphate
Calcium nitrite
Ammonium hypochlorite
Ammonium fluoride

46. Writing Formulas
If you’re given a name and asked to write the formula, there are some separate steps to take.
Look at the name. Figure out the symbols for the cation and anion. Write the symbols by each other.
Figure out the charge on each ion and write it to the upper right of the element symbol.
Balance the charges—figure out how many of each ion you would need to have the same amount of positives as negatives.
Write how many of each element/ion you need as a SUBSCRIPT written AFTER the element symbol.

47. Example Write the formula for Magnesium nitrate.
Step 1: Write the symbols for the cation and anion.
Magnesium: Mg
Nitrate (check your ion sheet!): NO3

48. Example
Step 2: Figure out and write the charges. Mg has 2 valence electrons and will lose them both to look like a noble gas, giving it a 2+ charge. According to the ion sheet, NO3 has a -1 charge. Mg2+ NO3-

49. Example
Step 3: Balance the charges. You need the charges to cancel out—meaning that for every + you have, you need a – and vice versa. Mg has 2+ NO3 has 1 – To get a second – to balance out the second +, you need two nitrates!

50. Example
Mg + - NO3 + - NO3 Since we need one Mg and two NO3, we write our formula as MgNO32 But if we leave it like that it looks like we are saying we need 32 oxygens! To show that we need 2 nitrates and not 32 oxygens, we write nitrate in parentheses. Mg(NO3)2

51. Practice Na3P Ca(NO3)2 NH4CN Al2S3
Write formulas for the following compounds.
Sodium phosphide
Calcium nitrate
Ammonium cyanide
Aluminum sulfide
Na3P
Ca(NO3)2
NH4CN
Al2S3

52. It gets weird: Transition Metals
Most transition metals have multiple possible charges. We have to identify which charge we are talking about for any transition metal in a compound. We identify the transition metal charge using Roman numerals.

53. Roman Numerals Recap
Number: Roman Numeral: 1 I 2 II 3 III 4 IV 5 V 6 VI

54. Writing names with transition metals
Step 1. Figure out the charge on the transition metal based on the formula. Remember that the cations and anions have to balance charges. WF5 Each F anion has a -1 charge. There are 5 F ions. That means there is a total of -5 charge coming from the F ions. The W cation has to balance out the -5 from the F ions.

55. Writing names with transition metals
If all the F add up to -5, the W has to balance it out.
If there are 5 negatives, we need 5 positives
That means W must have a +5 charge!

56. Writing names with transition metals
Step 2: Once you know the charge on the transition metal, write the name of the transition metal and then the charge, as a Roman numeral, in parenthesis.
W > Tungsten (V)
Step 3: write the name of the anion
If it is a monatomic anion, make sure you change the ending to “ide”
If it is a polyatomic anion, write the whole ion’s name.
WF > Tungsten (V) fluoride

57. Practice CrBr3 Chromium (III) bromide Cu2S Copper (I) sulfide Fe(NO3)2
NiSO4
V3(PO4)5
Ti2CrO4
AuN
Chromium (III) bromide
Copper (I) sulfide
Iron (II) nitrate
Nickel (II) sulfate
Vanadium (V) phosphate
Titanium (II) chromate
Gold (III) nitride

58. Writing formulas with transition metals
Writing formulas for compounds with transition metals is exactly the same as writing formulas for compounds without them…only easier! Because the name of the compound tells you the charge on the cation!

59. Writing formulas with transition metals
Example: Cobalt (III) nitrite Co3+ NO2- You need three negatives to balance the cobalt’s +3…so you need three nitrites to balance the cobalt! Co(NO2)3

60. Practice FeCl3 Cu2O HgI2 Mn2(Cr2O7)3 PbSO3 Sn3(PO3)4
Iron (III) chloride
Copper (I) oxide
Mercury (II) iodide
Manganese (III) dichromate
Lead (II) sulfite
Tin (IV) phosphite
FeCl3
Cu2O
HgI2
Mn2(Cr2O7)3
PbSO3
Sn3(PO3)4