CHEMISTRY
2013-2014
Atomic review
and
NOMENCLATURE
Chemistry
Unit 4
Oct. 10-31, 2013
ATOMIC REVIEW
Atoms are the basic building block of all matter. They are made of three smaller components
that affect the way they behave. All atoms have a similar structure, just variations of the three
components. Knowing how atoms are constructed helps to understand how the chemists
organize them in the Periodic Table.
Atomic structure is divided into two
parts: the nucleus and the electron cloud.
The nucleus is the center of the atom and
contains all the material that makes up
the atom’s mass.
The nucleus
determines what kind of atom it is.
All nuclei have protons and neutrons.
Proton particles are always positively
charged and they determine the atomic number of an atom, and therefore what kind of atom it
is. Atoms are all arranged on the Periodic Table according to how many protons they have!
Chemists have determined that one proton has a mass of one atomic mass unit (amu). Neutron
particles have no charge, they are neutral. The neutrons are with the protons in the nucleus and
together they make up the atomic MASS. Neutron numbers can change in the real world. In
fact, most atoms have many forms of different neutron numbers. This affects the atom’s atomic
MASS and is the reason that the mass is a collective average of all the different forms of that one
atom. The different forms are called isotopes. An isotope is one type of atom with the same
number of protons (changing the proton number changes the type of atom!) and a different
number of neutrons.
The electron cloud is the area around the nucleus where electrons can be found. Electrons are
tiny, tiny particles that are negativity charged. Electrons are so tiny that they have no measureable
mass! So, chemists DO NOT include the electron in the atomic mass calculations. The
electron’s actual mass is 1/1836 amu or 9.10938188 × 10-28 grams. It would take nearly 2000
electrons to equal one proton! Electrons move so fast that at they cannot be located at any one
place at any one time.
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PERIODIC TABLE
The Periodic Table is an essential tool of every chemist. The table is constructed of horizontal
rows that are called PERIODS and vertical rows that are called COLUMNS or FAMILIES.
The table is divided by a stair-step into METALS and NON-METALS. Notice that there are
many more metals on the chart than there are non-metals because everything to the left of the
bold stair-step and all of the elements at the bottom of the chart are METALS. Non-metals are
to the right of the stair-step. Those elements (with the exception of aluminum) that touch the
stair-step along an entire edge are called semi-metals or metalloids, and have characteristics of
both metals and non-metals.
All METALS share several characteristics in common:
(1) Luster (shiny); some have more luster than others, but all metals have some shine
(2) All metals are silver- or gray-colored except gold and copper
(3) All metals will conduct electricity – some conduct better than others, but all metals
will conduct electricity to some degree. Gold is considered to be the best electrical
conductor followed closely by silver, copper, and aluminum
(4) Ductile – can be pulled into a wire – think of pulling Silly Putty apart slowly
(5) Malleable – can be hammered into a thin sheet or molded by a hammer – some are
more malleable than others. Gold is probably the most malleable, followed by silver and
copper
(6) Metals always lose electrons from their outer energy level to form positive ions
that are called cations. Since the positively charged ion will be attracted to the negative
electrode (opposites attract), the ion attracted to the cathode is called the CATION.
(6) The Roman numeral at the top of the column on the Periodic Chart is the number of
electrons in its outermost energy level, and these are the electrons that the metal will lose
(all of them)
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All NON-METALS have (almost) opposite characteristics:
(1) No luster
(2) Frequently powdery, liquid, or gaseous
(3) Most are colored rather than silvery
(4) Do not conduct electricity (non-conductors) except some of the metalloids that are
used in computer chips
(5) No ductility
(6) No malleability
(7) Always gain electrons into their outer energy level until they have 8 and form
negative ions that are called anions. Since a negatively charged particle will be
attracted to the positive electrode (opposites attract), the ion that is attracted to the anode
is called the ANION
(8) The Roman numeral at the top of the column on the Periodic Chart is the number of
electrons in that atom’s outermost energy level, and non-metals must gain enough
electrons here to make a total of 8 in the outermost energy level.
Positive ions (cations) have more protons than they have electrons since metals ALWAYS
LOSE electrons. This results in the ion having a positive charge.
Negative ions (anions) have gained electrons in their outermost energy levels and, therefore,
have more electrons than protons. This results in the ion having a negative charge.
OXIDATION NUMBER is the overall charge on an ion after it has lost electrons (metals) or
gained electrons (non-metals). Oxidation numbers can be determined by looking at the Periodic
Chart for the "A" column elements, but usually it is easier just to memorize the oxidation number
associated with every ion rather than having to look it up every time. Ions are written as the
chemical symbol with a small super script of its charge directly to the right of the symbol.
Practice writing these elements using ion notation:
1. Calcium
2. Oxygen
3. Carbon
4. Potassium
5. Chlorine
6. Argon
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7. Lithium
8. Boron
9. Barium
10. Zinc
11. Sodium
12. Magnesium
CHEMISTRY
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NAMING A COMPOUND
When ions are combined together to form compounds, the overall charge of the compound
that results must be "zero" or neutral.
For example, if an ion of potassium (whose charge is +1) combines with an ion of chlorine
(whose charge is -1), the compound that results is electrically neutral as written in a 1:1 ratio of
ions: one potassium ion with a charge of +1 will exactly neutralize one chlorine ion with a
charge of –1, so the formula for the compound is written simply KCl (one K to one Cl).
However, if an ion of magnesium (whose charge is +2) combines with an ion of chlorine (whose
charge is -1), the compound that forms must be electrically neutral, so, therefore, it takes two of
the chlorine ions (with a charge of -1 each) to neutralize one of the magnesium ions whose
charge is +2. When we write the formula, it must be written MgCl2 to make it absolutely neutral.
The atoms are present in a ratio of 1:2. The number that shows us that there must be more than
one of a particular ion present to make the compound neutral is always written as a
SUBSCRIPT.
Notice that in writing chemical formulas, the metal ion is always written first and the nonmetal ion is written last.
Example 1: Write a correct formula for the compound that would form between:
(a) lithium and fluorine
(b) calcium and sulfur
(c) cesium and oxygen
(d) aluminum and oxygen
(e) sodium and sulfur
(f) aluminum and chlorine
(g) potassium and oxygen
4A - WRITING CORRECT FORMULAS I WORKSHEET
Write the correct formula for the following combinations:
1. Cl and Ba
6. O and Sr
2. K and S
7. Cu (1+) and Se
3. Al and C
8. H and P
4. Fe (3+) and O
9. O and K
5. S and Li
10. Br and Ba
Sometimes there is more than one molecule of a compound present. We use coefficients or a
number in front of a formula to show how many molecules of that compound are present. When
a coefficient is in front of a chemical formula, you must multiply the coefficient times the
subscript to find the right number of each atom in the formula.
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Coefficients: How many of the listed element in each formula:
11. H in 3H2SO4
12. S in 2Al2(SO4)2
13. N in 3HNO3
14. O in 4Cu(OH)2
15. Li in 5Li2CO3
The metals that are located in the middle section of the Periodic Chart (B columns) have
oxidation numbers that must be memorized because you cannot necessarily predict them from
looking at the column numbers. These elements are known as transition elements and the ones
you need to know are listed on your Table of Ions to Know. MEMORIZE THEM NOW!!!!
IONIC AND MOLECULAR COMPOUNDS
We will basically be writing and naming two different types of compounds – ionic and
molecular.
Ionic compounds are those compounds that are made up of:
(1) a metal and a non-metal
(2) a metal and a polyatomic ion
(3) ammonium ion and a non-metal
(4) ammonium ion and a polyatomic ion
When naming BINARY (two elements only) ionic compounds (i.e., a metal and a non-metal):
(1) call the entire name of the metal
(2) shorten the name of the non-metal (usually at the 2nd vowel from the end of the
word) and add the suffix "ide". Therefore, KCl would be called potassium chloride, not
potassium chlorine.
Example 2: Name the following binary ionic compounds:
(1) MgBr2
(2) NaF
(3) Al2O3
(4) CdO
(5) ZnS
(6) Na2O
(7) K3N
Some metals have more than one oxidation number and when you name them you must indicated
which of the oxidation numbers you are using. For these you must use a roman numeral to
indicate the oxidation number of the cation.
There are two naming systems for compounds containing these metals:
(1) The "old" system that uses the suffix "ic" for the higher oxidation number and "ous"
for the lower oxidation number. So, therefore, we have cupric and cuprous, ferric and
ferrous, plumbic and plumbous, stannic and stannous, and mercuric and mercurous
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(2) The “new” IUPAC system – some metals were found to have more than two
oxidation numbers, so we adopted a new system of naming called the IUPAC
(International Union of Practical and Applied Chemists) which uses the element name
and a Roman numeral (in parenthesis) written after the name. So, we can also name the
compounds copper(I) and copper(II), iron(III) and iron(II), lead(IV) and lead(II), tin(IV)
and tin(II), and mercury(II) and mercury(I).
Because we are still in a transition period to the new naming system, you will not be required to
know both of these systems, but you should at least be familiar with them because many of the
labels on chemical bottles still use the old system. You must be able to use the new system!
Know where to look up the old names just in case they appear on worksheets or in reading
material.
Example 3: Write correct formulas for the following:
(1) iron(III) oxide
(2) tin(IV) chloride
(3) lead(IV) oxide
(4) tin(II) sulfide
(5) mercury(II) bromide
(6) mercury(I) fluoride
(7) copper(II) nitride
(8) iron(II) iodide
Example 4: Name the following compounds:
(1) FeCl2
(3) CuS
(5) CuI
(2) SnO
(4) Hg2I2
(6) PbO2
4B - WRITING AND NAMING BINARY COMPOUNDS WORKSHEET
Write a CORRECT chemical formula for each of the following binary compounds:
1. cadmium sulfide
19. Tin(IV) oxide
2. iron(III) oxide
20. Mercury(I) iodide
3. magnesium nitride
21. tin(II) oxide
4. Copper(II) bromide
22. aluminum sulfide
5. lead(IV) oxide
23. copper(I) phosphide
6. strontium sulfide
24. barium sulfide
7. tin(II) iodide
25. cadmium bromide
8. aluminum fluoride
26. mercury(I) oxide
9. silver bromide
27. aluminum fluoride
10. Copper(I) oxide
28. Copper(II) chloride
11. Mercury(I) phosphide
29. Tin(IV) nitride
12. cesium chloride
30. lithium oxide
13. Lead(II) nitride
31. zinc iodide
14. Iron(III) iodide
32. lead (II) chloride
15. Copper(II) phosphide
33. iron (II) fluoride
16. Mercury(II) iodide
34. silver nitride
17. copper(I) nitride
35. tin (II) sulfide
18. potassium chloride
36. silver sulfide
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Write out in words the name of each of the following compounds:
1. CuCl2
16. PbF2
2. FeO
17. Cs3N
3. Na3N
18. Hg2O
4. SnS
19. SnCl4
5. Hg2I2
20. FeI2
6. PbBr2
21. SrO
7. CaF2
22. Cs2S
8. Cu3P
23. FeS
9. SnS2
24. (Hg2)3P2
10. ZnF2
25. K3P
11. LiI
26. FeCl3
12. CuCl
27. Ag3N
13. Na2S
28. NaF
14. Hg3P2
29. Sn3P4
15. AgBr
30. AlCl
POLYATOMIC IONS
Polyatomic ions are atom groups that usually stay together; basically, ions that are composed of
several different elements. These elements stay together in chemical reactions and the entire
group has a charge (oxidation number). There is no way you can predict the formulas nor the
oxidation numbers of these, so they must be memorized now for you to be able to write correct
chemical formulas.
These polyatomic ions follow a predictable pattern once you have learned the most common of
each ion:
1. The most common ion has a suffix of –ate. It is difficult to predict the formulas of
these so they must be memorized. (i.e., chlorate is ClO3−1)
2. If you add one oxygen to the most common ion, it does not change the charge but it
does change the name. To name it, we add a prefix of per- with the suffix –ate. (i.e.,
perchlorate is ClO4−1)
3. If you lose one oxygen from the most common ion, it does not change the charge but it
does change the name. To name it, we have no prefix but use the suffix –ite. (i.e., chlorite
is ClO2−1)
4. If you lose two oxygen from the most common ion, it does not change the charge but it
does change the name. To name it, we use the prefix hypo- with the suffix –ite. (i.e.,
hypochlorite is ClO−1)
If you must add a subscript after a polyatomic ion, the polyatomic ion must be placed in
parentheses first and the subscript added outside the parenthesis!! No exceptions!!!!
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Example 5: Write correct chemical formulas for each of the following:
(1) aluminum nitrate
(2) copper(II) sulfate
(3) zinc chlorate
(4) magnesium phosphate
(5) ammonium chromate
(6) silver nitrite
(7) aluminum permanganate
4C - WRITING CORRECT FORMULAS II WORKSHEET
Combine the two and write the correct formula. Remember: More than one of a
polyatomic ion requires parenthesis. The positive atom or ion is written first.
1. Na, Cl
11. NH4, CO3
2. Ca, NO3
12. H, PO4
3. Fe(3+), SO4
13. Na, HCO3
4. K, O
14. Fe(2+), Br
5. Al, MnO4
15. Ca, C2H3O2
6. Pb(4+), SO3
16. H, O2
7. Ba, I
17. Rb, SO3
8. Cu(2+), ClO
18. H, CO3
9. Fe(3+), S
19. Ra, OH
10. Zn, OH
4D - WRITING AND NAMING POLYATOMIC COMPOUNDS WORKSHEET
Write a correct formula for each of the following polyatomic compounds:
1. lead(II) chlorate
16. iron(II) cyanide
2. zinc phosphate
17. potassium nitrite
3. sodium carbonate
18. magnesium phosphate
4. copper(I) sulfite
19. tin(II) chlorate
5. tin(II) bicarbonate
20. cesium permanganate
6. mercury(I) cyanide
21. ammonium phosphite
7. aluminum dichromate
22. iron(III) acetate
8. tin(IV) nitrite
23. lead(IV) chlorate
9. cesium hydrogen sulfite
24. barium dichromate
10. barium perchlorate
25. strontium hydroxide
11. lithium phosphite
26. mercury(I) permanganate
12. tin(IV) sulfate
27. copper(II) nitrite
13. lead(IV) permanganate
28. ammonium acetate
14. cadmium bisulfate
29. cesium bisulfate
15. copper(II) perchlorate
30. copper(I) chlorate
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Write the NAME of each of the following compounds:
1.
2.
3.
4.
5.
6.
Pb3(PO4)2
Cu2CO3
Fe(C2H3O2)2
CaSO4
K2Cr2O7
Mg3(PO4)2
KHCO3
7.
8. Cu2CO3
9. Fe(NO2)2
10. AgNO3
11. Ba(ClO4)2
12. Pb(CO3)2
13. Cd(OH)2
14. SnSO4
15. Zn(HCO3)2
16. Pb(SO4)2
17. Sn(OH)2
18. Hg2(NO2)2
19. (NH4)2CrO4
20. Cu2CO3
Compounds can also be written which consist of TWO NON-METALS. In this case, one of the
non-metals must assume a positive oxidation number and will be written first. You do not need
to worry about which of the non-metals is more like to assume the positive oxidation number –
you just need to be able to recognize that they are “special” compounds and be able to name two
non-metals bonded together in a “special” way.
When two non-metals combine to form a compound, it is called a MOLECULAR
COMPOUND and the non-metals are bonded covalently (share electrons).
To name molecular compounds, we use a series of prefixes to indicate the number of atoms of
each element which are present. These prefixes should not be used in naming ionic
compounds.
The prefixes are:
1 mono-*
6 hexa2 di7 hepta3 tri8 octa4 tetra9 nona5 penta10 deca* mono- has recently been removed from the nomenclature although it will continue to be
used by many chemists for years; thus, carbon monoxide should now be carbon oxide
If you wish to name Cl2O7, a molecular compound since it contains two non-metals, use the
prefix to indicated how many chlorines are present in the molecule and call the ENTIRE first
element’s name (not shortened nor modified) i.e., dichlorine. Then use a prefix to indicate
how many atoms of the second element are present and shorten its name at the second vowel
from the end of the name and add “ide”, i.e., heptaoxide.
Example 6: Name the following molecular compounds
(a) N2O5
(b) SO3
(c) CO
(d) P4O10
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ORGANIC COMPOUNDS
Compounds in which carbon is written FIRST are also named in a “special” way. We will
be interested in organic compounds that contain carbon and hydrogen. These are called
hydrocarbons and will be of two general types – straight chain and cyclic. The straight chain
hydrocarbons will always fit the general formula CnH2n + 2 and their names must be memorized
based on how many carbons they contain. After memorizing the first four, the names are
intuitive since they are the same as the prefix that means that particular number (Also, these
prefixes are the same as those used in geometry).
A cyclic (circular) hydrocarbon can be recognized by the fact that it will fit the general
formula C2H2n and the same type of naming system will be used EXCEPT the prefix
“cyclo” will be placed in front of the name.
The hydrocarbons names are as follows:
CH4
methane
C6H14 hexane
C2H6 ethane
C7H16 heptane
C3H8 propane
C8H18 octane
C4H10 butane
C9H20 nonane
C5H12 pentane
C10H22 decane
There are hundreds more of these, and they are named much like numbers are put together in a
foreign language, but we will not learn any but these.
For the cyclics, there is no circular hydrocarbon that contains one or two carbons because it is
impossible to write them in a circle with so few atoms, but, beginning with 3 carbons:
C3H6 cyclopropane
C7H14 cycloheptane
C4H8 cyclobutane
C8H16 cyclooctane
C5H10 cyclopentane
C9H18 cyclononane
C6H12 cyclohexane
C10H20 cyclodecane
Example 7: Name the following hydrocarbons:
(a) C4H10
(b) C8H18
(c) C2H6
(d) C4H8
(e) C7H16
(f) C5H10
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4E - NAMING HYDROCARBONS AND MOLECULAR COMPOUNDS WORKSHEET
Write a correct formula for each of the following:
1. dinitrogen trioxide
3l. ethane
2. cyclobutane
32. methane
3. sulfur dioxide
33. carbon disulfide
4. decane
34. sulfur trioxide
5. diarsenic trioxide
35. octane
6. cyclononane
36. dinitrogen oxide
7. pentane
37. carbon oxide
8. diphosphorus pentoxide
38. nonane
9. nitrogen dioxide
39. hexane
10. sulfur trioxide
40. triargon dichloride
11. tetraphosphorus decoxide
41. propane
12. cyclopropane
42. oxygen difluoride
13. heptane
43. cyclopentane
14. butane
44. tricarbon oxide
15. diarsenic pentoxide
45. cyclodecane
16. dichlorine monoxide
46. cyclopentane
17. silicon tetrachloride
47. silicon dioxide
18. dihydrogen monoxide
48. sulfur trioxide
19. sulfur tetrafluoride
49. krypton disulfide
20. carbon tetrachloride
50. cyclooctane
21. sulfur hexaiodide
51. diphosphorus trifluoride
22. tellurium dioxide
52. selenium dioxide
23. cyclohexane
53. carbon dioxide
24. diarsenic tetroxide
54. difluorine dichloride
25. nitrogen monoxide
55. dichlorine trifluoride
26. nitrogen dioxide
56. selenium dioxide
27. diphosphorus trioxide
57. carbon ditelluride
28. phosphorus pentachloride
58. tribromine monoxide
29. cycloheptane
59. diargon disulfide
30. arsenic pentiodide
60. heptasulfur nonoxide
NAMING ACIDS
Compounds that have hydrogen as their cation are usually named as acids unless you can
determine by the physical state that they should be named normally. If there is (aq) beside the
compound whose cation is hydrogen, it is an acid and will be named as such. If there is (s), (l), or
(g) beside the compound whose cation is hydrogen, it should be named normally. Here are the
acids that you should memorize now:
HCl(aq)
hydrochloric acid
stomach acid
H2SO4 (aq)
sulfuric acid
battery acid
HNO3(aq)
nitric acid
used to pure tobacco leaves, stains your
hands orange
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H3PO4(aq)
phosphoric acid
used in all soft drinks as a preservative
HC2H3O2(aq)
acetic acid
vinegar; used in salad dressings
There are actually 3 simple rules for name acids so you can name any acid (even if it doesn’t
exist):
1. For binary acids, we use the prefix hydro- attached to the name of the anion and
change the –ide ending to –ic. Then add the word acid. (i.e., HCl is hydrochloric acid)
2. For ternary acids, we do not use the hydrogen in any way except to help us identify
that it is an acid. We actually use only the anion and we look at the ending of the anion. If
a prefix is present, it stays with the word.
a. If the anion ends in –ate, then change that ending to –ic acid. (i.e., HClO3 is
hydrogen chlorate but become choric acid)
b. If the anion ends in –ite, then change that ending to –ous acid. (i.e., HClO2 is
hydrogen chlorite but become chlorous acid)
Example 8:
a. H3PO4
b. H3PO2
c. HI
d. HIO3
e. H2S
f. H2SO3
4F - NAMING AND WRITING ACIDS
Name the following acids the MOST CORRECT way:
1. HClO2
2. HBr
3. H3PO4
4. HClO
5. H2SO4
Write the formula for the following acids:
6. hydrosulfuric acid
7. sulfurous acid
8. perchloric acid
9. hydrofluoric acid
10. iodic acid
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DIATOMIC MOLECULES
Most elements can exist and are written as a single atom, such as copper is written as Cu, zinc is
written as Zn, carbon is written as C, etc. But there are 7 elements that cannot exist as a
single atom and must be written as two atoms together when they occur free in nature or
uncombined into a compound. These elements are called DIATOMIC and they also must be
memorized:
H2
hydrogen gas, pure hydrogen, hydrogen, uncombined hydrogen or dihydrogen
O2
oxygen gas, pure oxygen, oxygen, uncombined oxygen, or dioxygen
N2
nitrogen gas, pure nitrogen, nitrogen, uncombined nitrogen, or dinitrogen
F2
fluorine gas, pure fluorine, fluorine, uncombined fluorine, or difluorine
Cl2
chlorine gas, pure chlorine, chlorine, uncombined chlorine, or dichlorine
Br2
liquid bromine, pure bromine, bromine, uncombined bromine, or dibromine
I2
iodine crystals, solid iodine, pure iodine, uncombined iodine, or diiodine
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TABLE OF IONS AND OXIDATION NUMBERS
POSITIVE IONS (cations)
NEGATIVE IONS (anions)
Hydrogen
H+1
Lithium
Li+1
Sodium
Na+1
Potassium
K+1
Cesium
Cs+1
Silver
Ag+1
Copper (I)
Cu+1
(also called cuprous)
Mercury (I)
Hg2+2
(also called mercurous)
Ammonium
NH4+1
Br-1
Cl-1
F-1
I-1
Oxide
Sulfide
O-2
S-2
Nitride
Phosphide
N-3
P-3
Acetate
C2H3O2-1
Cyanide
CN-1
Hydroxide
OH-1
Nitrite
NO2-1
Nitrate
NO3-1
Hydrogen sulfite
HSO3-1
(also called bisulfite)
Hydrogen sulfate
HSO4-1
(also called bisulfate)
Hydrogen carbonate HCO3-1
(also called bicarbonate)
Permanganate
MnO4-1
Hypochlorite
ClO-1
Chlorite
ClO2-1
Chlorate
ClO3-1
Perchlorate
ClO4-1
Barium
Ba+2
Magnesium
Mg+2
Calcium
Ca+2
Strontium
Sr+2
Zinc
Zn+2
Cadmium
Cd+2
Copper (II)
Cu+2
(also called cupric)
Iron (II)
Fe+2
(also called ferrous)
Lead (II)
Pb+2
Mercury (II)
Hg+2
Tin (II)
Sn+2
Aluminum
Al+3
Iron (III)
Fe+3
(also called ferric)
Tin (IV)
Lead (IV)
Bromide
Chloride
Fluoride
Iodide
Sn+4
Pb+4
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Hydrogen Phosphate
Silicate
Carbonate
Chromate
Dichromate
Sulfite
Sulfate
Oxalate
Peroxide
Tartrate
Thiosulfate
HPO4-2
SiO3-2
CO3-2
CrO4-2
Cr2O7-2
SO3-2
SO4-2
C2O4-2
O2─2
C4H4O62
S2O3─2
Phosphite
Phosphate
Arsenate
PO3-3
PO4-3
AsO4-3