1. Warmup 2/14
Write the longhand and shorthand electron configurations for the following:
Phosphorous (P)
Calcium (Ca)
Barium (Ba)

2. “Chemical Names and Formulas” – Part I
H2O
“Chemical Names and Formulas” – Part I

3. Atoms and Ions Atoms are electrically neutral.
Because there is the same number of protons (+) and electrons (-).
Ions are atoms, or groups of atoms, with a charge (positive or negative)
They have different numbers of protons and electrons.
Only electrons can move, and ions are made by gaining or losing electrons.

4. F1- O2- An Anion is… A negative ion. Has gained electrons.
Nonmetals can gain electrons.
Charge is written as a superscript on the right.
Has gained one electron (-ide is new ending = fluoride)
F1-
O2-
Gained two electrons (oxide)

5. K1+ Ca2+ A Cation is… A positive ion. Formed by losing electrons.
More protons than electrons.
Metals can lose electrons
K1+
Has lost one electron (no name change for positive ions)
Ca2+
Has lost two electrons

6. Oxidation Numbers
Number given to an element to show how many electrons it has lost, gained or shared when forming a compound
Ex: NaCl
To form this compound:
Na lost 1 e-, Cl gained 1 e-

7. Assigning Oxidation Numbers
Rule #1 For Groups 1A – 4A: Take number before “A” and add (+) in front
Na in group 1A = +1 O.N.
Rule #2 For Groups 5A-8A: Take number before “A” and subtract 8 from it
Cl in group 7A = 7-8 = -1 O.N.

8. Oxidation numbers for transition metals (Groups 3-12)
Transition metals have multiple oxidation states
Cu +1 Cu +2
Fe+2, Fe +3
Pb +2, Pb +4

9. Writing Chemical formulas
Write symbol of element with (+) oxidation number first
Write symbol of element with (-) oxidation number
Ex. Na+1 Cl -1

10. Writing Chemical Formulas
If Numbers add up to zero cross out charges and write together
Na+1 Cl -1 = NaCl
Ca +2 O -2 = CaO

11. Writing Chemical Formulas
If oxidation numbers don’t add up to zero criss-cross the numbers (Al and S)
Al +3S-2 = Al2S3

12. Predicting Ionic Charges
Group 1A:
Lose 1 electron to form 1+ ions
H1+
Li1+
Na1+
K1+
Rb1+

13. Predicting Ionic Charges
Group 2A:
Loses 2 electrons to form 2+ ions
Be2+
Mg2+
Ca2+
Sr2+
Ba2+

14. Predicting Ionic Charges
Loses 3
electrons to form
3+ ions
Group 3A:
B3+
Al3+
Ga3+

15. Predicting Ionic Charges
Neither! Group 4A elements rarely form ions (they tend to share)
Do they lose 4 electrons or gain 4 electrons?
Group 4A:

16. Predicting Ionic Charges
Nitride
Gains 3
electrons to form
3- ions
Group 5A:
P3-
Phosphide
As3-
Arsenide

17. Predicting Ionic Charges
Oxide
Gains 2
electrons to form
2- ions
Group 6A:
S2-
Sulfide
Se2-
Selenide

18. Predicting Ionic Charges
Gains 1 electron to form
1- ions
Group 7A:
F1-
Fluoride
Br1-
Bromide
Cl1-
Chloride
I1-
Iodide

19. Predicting Ionic Charges
Stable noble gases do not form ions!
Group 8A:

20. Predicting Ionic Charges
Group B elements:
Many transition elements
have more than one possible oxidation state.
Note the use of Roman numerals to show charges
Iron (II) = Fe2+
Iron (III) = Fe3+

21. Warmup Briefly compare/contrast anions and cations.
What are oxidation numbers?
What is the correct chemical formula for the combination of aluminum and sulfur?

22. “Chemical Names and Formulas” – Part II

23. Naming cations
Two methods can clarify when more than one charge is possible:
Stock system – uses roman numerals in parenthesis to indicate the numerical value
Classical method – uses root word with suffixes (-ous, -ic)
Does not give true value

24. Naming cations We will use the Stock system.
Cation - if the charge is always the same (like in the Group A metals) just write the name of the metal.
Transition metals can have more than one type of charge.
Indicate their charge as a roman numeral in parenthesis after the name of the metal

25. Examples: (Sodium…Group IA) = Na1+ (Calcium…Group IIA) = Ca2+
(Iron (III)…Transition Element) = Fe3+
(Iron (II)…Transition Element) = Fe2+

26. Examples: Potassium ion = K1+ Magnesium ion = Mg2+
Copper (II) ion = Cu2+

27. Anions are always the same charge
Naming Anions
Anions are always the same charge
Change the monatomic element ending to – ide
F1- a Fluorine atom will become a Fluoride ion.

28. Examples:
Chloride = Cl1-
Nitride = N3-
Bromide = Br1-

29. Examples:
Sulfide ion = S2-
Iodide ion = I1-
Phosphide ion = P3-

30. Polyatomic ions are…
Groups of atoms that stay together and have an overall charge, and one name.
Usually end in –ate or -ite
Acetate: C2H3O21-
Nitrate: NO31-
Nitrite: NO21-
Permanganate: MnO41-
Hydroxide: OH1-

31. If the polyatomic ion begins with H, combine the word hydrogen with the other polyatomic ion present…
Ex. H1+ + CO32- → HCO31-
hydrogen + carbonate → hydrogen carbonate ion

32. Things to look for:
If cations have ( ), the number in parenthesis is their charge.
If anions end in -ide they are probably off the periodic table (Monoatomic)
If anion ends in -ate or –ite, then it is polyatomic

33. Binary Ionic Compounds
Contain 2 different elements
Name the metal first, then the nonmetal as -ide.
Use name of a metal with a fixed charge
Groups 1A, 2A, 3A
and Ag, Zn, and Cd
Examples:
NaCl sodium chloride
ZnI2 zinc iodide
Al2O3 aluminum oxide

34. Naming Binary Covalent Compounds (Molecular Compounds)
Two nonmetals
Name each element
End the last element in -ide
Add prefixes to show more than 1 atom

35. Molecular compounds are…
made of just nonmetals
smallest piece is a molecule
can’t be held together by opposite charge attraction
can’t use charges to figure out how many of each atom (there are no charges present)

36. Molecular compounds are easier!
Ionic compounds use charges to determine how many of each.
You have to figure out charges.
May need to criss-cross numbers.
Molecular compounds: the name tells you the number of atoms.
Uses prefixes to tell you the exact number of each element present!

37. Prefixes 1 = mono- 2 = di- 3 = tri- 4 = tetra- 5 = penta- 6 = hexa-
7 = hepta-
8 = octa-

38. Prefixes Prefix name Prefix name -ide 9 = nona- 10 = deca-
To write the name, write two words:
One exception is we don’t write mono if there is only one of the first element.
Normally, we do not have double vowels when writing names (oa oo)
Prefix
name
Prefix
name
-ide

39. = dinitrogen monoxide (also called nitrous oxide or laughing gas)
Examples:
= dinitrogen monoxide (also called nitrous oxide or laughing gas)
N2O
NO2
Cl2O7
CBr4
CO2
BaCl2
= nitrogen dioxide
= dichlorine heptoxide
= carbon tetrabromide
= carbon dioxide
(This one will not use prefixes, since it is an ionic compound!)

40. Examples:
diphosphorus pentoxide = P2O5
sulfur hexafluoride = ?

41. Naming Ternary Compounds
Contain at least 3 elements
Name the nonmetals as a polyatomic ion
Examples:
NaNO3 Sodium nitrate
K2SO4 Potassium sulfate
Al(HCO3)3 Aluminum bicarbonate
or aluminum hydrogen
carbonate

42. Practice… sodium chloride lithium oxide calcium bromide
antimony tribromide
chlorine dioxide
dinitrogen trioxide
P4S5
Si2Br6
NF3
aluminum carbonate
ammonium sulfate

43. Warmup 2/22 Write formulas for the following:
aluminum oxide
beryllium oxide
copper (II) chloride
Write names for the following: HI
IF5
NF3

44. “Chemical Names and Formulas” – Part III

45. Acids are…
Compounds that give off hydrogen ions (H1+) when dissolved in water
Will start the formula with H.
There will always be some Hydrogen next to an anion.
The anion determines the name.

46. Rules for Naming acids:
If the anion attached to hydrogen ends in -ide, put the prefix hydro- and change -ide to -ic acid
HCl - hydrogen ion and chloride ion = hydrochloric acid
H2S hydrogen ion and sulfide ion = hydrosulfuric acid

47. Naming Acids
If the anion has oxygen in it, then it ends in -ate or -ite
change the suffix -ate to -ic acid (use no prefix)
Example: HNO3 Hydrogen and nitrate ions = Nitric acid
change the suffix -ite to -ous acid (use no prefix)
Example: HNO2 Hydrogen and nitrite ions = Nitrous acid

48. Naming Acids ____-ide ____-ate ____-ite hydro-___-ic acid
Normal ending
____-ide
____-ate
____-ite
Acid name is…
hydro-___-ic acid
_____-ic acid
_____-ous acid

49. Examples: HF = hydrofluoric acid H2SO4 = sulfuric acid
H2SO3 = sulfurous acid

50. Writing Acid Formulas – in reverse!
Hydrogen will be listed first
The name will tell you the anion
Be sure the charges cancel out.
-ate anion comes from –ic ending
-ite anion comes from –ous ending

51. Examples: acetic acid = hydrogen acetate
carbonic acid = hydrogen carbonate
phosphorous acid = hydrogen phosphite

52. Names and Formulas for Bases
A base is an ionic compound that produces hydroxide ions (OH1-) when dissolved in water
Bases are named the same way as other ionic compounds:
The name of the cation (which is a metal) is followed by the name of the anion (which will be hydroxide).

53. Names and Formulas for Bases
NaOH is sodium hydroxide
Ca(OH)2 is calcium hydroxide
To write the formula:
Write the symbol for the metal cation
followed by the formula for the hydroxide ion (OH1-)
then use the criss-cross method to balance the charges.

54. You Must Know These Acids!!!
HCl = hydrochloric acid
HNO3 = nitric acid
H2SO4 = sulfuric acid
HC2H3O2 = acetic acid
(CH3COOH) = short-hand for acetic acid (typically used for structural purposes…organic chemistry)

55. Examples for Bases: Magnesium hydroxide = Mg(OH)2
Iron (III) hydroxide = Fe(OH)3

56. Helpful to remember...
1. In an ionic compound, the net ionic charge is zero (criss-cross method)
2. An -ide ending generally indicates a binary compound
3. An -ite or -ate ending means there is a polyatomic ion that has oxygen
4. Prefixes generally mean molecular; they show the number of each atom

57. Helpful to remember...
5. A Roman numeral after the name of a cation is the ionic charge of the cation

58. Practice…(also classify as ionic, molecular, acid, or ternary)
BaSO3
lithium hydride
perchloric acid
PBr5
Fe2O3
dinitrogen monoxide HI
ammonium phosphate
MgS
copper (II) chloride

59. ANSWERS… barium sulfite (ternary) LiH (ionic) HClO4 (acid)
phosphorus pentabromide (molecular)
iron (III) oxide (ionic…transition element)
N2O (molecular)
hydroiodic acid (acid)
(NH4)3PO4 (ternary)
magnesium sulfide (ionic)
CuCl2 (ionic…transition element)