Common Ions
Note that there are patterns. Flash cards help. Please know formulas, names, charges.
In formulas, the cation is listed first, followed by the anion.
In names, the cation precedes the anion.
1
1A
1
H
All monatomic ions formed by main group elements in columns 1A, 2A, and 7A
Nonmetals in groups 5A and 6A; Al3+ in group 3A
Cations:
“metal name ion”
charge = A column number
“nonmetal root – ide” ion
charge = 8 – A column number
Anions:
NH4+
ammonium ion
OH-
hydroxide
C2H3O2- acetate
NO3NO2-
nitrate
nitrite
SO42SO32-
sulfate
sulfite
HSO4HSO3-
hydrogen sulfate
hydrogen sulfite
Cu+
Cu2+
Hg22+
Hg2+
Fe2+
Fe3+
copper (I)
copper (II)
mercury (I)
mercury (II)
iron (II)
iron (III)
Sn2+ tin (II)
Sn4+ tin (IV)
Pb2+ lead (II)
Pb4+ lead (IV)
CO32HCO3PO43PO33-
carbonate
hydrogen carbonate
phosphate
phosphite
HPO42HPO32H2PO4H2PO3-
hydrogen phosphate
hydrogen phosphite
dihydrogen phosphate
dihydrogen phosphite
18
8A
2
He
2
2A
13
3A
14
4A
15
5A
16
6A
17
7A
+1, -1
3
Li
4
Be
5
B
6
C
7
N
8
O
9
F
10
Ne
+1
11
Na
+2
12
Mg
13
Al
14
Si
-3
15
P
-2
16
S
-1
17
Cl
18
Ar
+1
19
K
+2
20
Ca
+3
31
Ga
32
Ge
-3
33
As
-2
34
Se
-1
35
Br
36
Kr
+1
37
Rb
+2
38
Sr
49
In
50
Sn
51
Sb
-2
52
Te
-1
53
I
54
Xe
+1
55
Cs
+2
56
Ba
+1, +3
81
Tl
+2, +4
82
Pb
83
Bi
84
Po
-1
85
At
86
Rn
+1
87
Fr
+2
88
Ra
+1, +3
113
Uut
+2, +4
114
Uuq
115
Uup
116
Uuh
-1
117
Uus
118
Uuo
+1
+2
3
3B
4
4B
5
5B
6
6B
7
7B
8
8B
9
8B
10
8B
11
1B
12
2B
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
39
Y
40
Zr
>1
41
Nb
>1
42
Mo
>1
43
Tc
+2, +3
44
Ru
>1
45
Rh
+2
46
Pd
+1, +2
47
Ag
+2
48
Cd
71
Lu
72
Hf
73
Ta
74
W
75
Re
76
Os
77
Ir
78
Pt
+1
79
Au
80
Hg
103
Lr
104
Rf
105
Db
106
Sg
107
Bh
108
Hs
109
Mt
110
Ds
+1, +3
111
Rg
+1, +2
112
Uub
Cobalt, chromium, manganese, and vanadium also
require Roman numerals. Look at the anion to determine the charge.
Ag+
H3O+
silver
hydronium
Cd2+
Ni2+
Zn2+
cadmium
nickel
zinc
CNSCNMnO4-
cyanide
thiocyanate
permanganate
ClO4perchlorate
ClO3chlorate
ClO2chlorite
ClOhypochlorite
(similarly for bromine and iodine)
CONGRATULATIONS! You’ve memorized the whole table.
CrO42Cr2O72C2O42O22-
chromate
dichromate
oxalate
peroxide
Common Ions (learn these)
Positive ions (cations)
+1 Charge
ammonium (NH4+)
copper (I) or cuprous (Cu+)
hydrogen (H+) “proton”
silver (Ag+)
hydronium ion (H3O+)
Group 1A cations (Li+, Na+, K+, Rb+, Cs+, Fr+)
Negative ions (anions)
-1 Charge
acetate (C2H3O2-)
cyanide CNdihydrogen phosphate (H2PO4-)
hydrogen carbonate or bicarbonate (HCO3-)
hydrogen sulfate of bisulfate (HSO4-)
hydroxide (OH-)
nitrate (NO3-), nitrite (NO2-)
perchlorate (ClO4-),chlorate (ClO3-),chlorite (ClO2-),
hypochlorite (ClO-)
permangante (MnO4-)
thiocyanate (SCN-)
Group 7A anions (F-, Cl-, Br-, I-) – ide ending
+2 Charge
-2 Charge
cadmium (Cd2+)
carbonate (CO32-)
chromium (II) or chromous (Cr2+)
chromate (CrO42-), dichromate(Cr2O72-)
cobalt(II) or cobaltous (Co2+)
hydrogen phosphate (HPO42-)
2+
copper(II) or cupric (Cu )
oxalate (C2O42-)
2+
iron(II) or ferrous (Fe )
oxide (O2-), peroxide (O22-)
2+
lead(II) or plumbous (Pb )
sulfate (SO42-), sulfite (SO32-)
2+
manganese(II) or manganous (Mn )
sulfide (S2-)
2+
mercury(I) or mercurous (Hg2 )
Group 6A anions (O2-, S2-, Se2-, Te2-) – ide ending
mercury(II) or mercuric (Hg2+)
nickel (Ni2+)
tin(II) or stannous (Sn2+)
zinc (Zn2+)
Group 2A cations (Be2+, Mg2+, Ca2+, Sr2+, Ba2+, Ra2+)
+3 Charge
-3 Charge
aluminum (Al3+)
phosphate (PO43-); phosphite (PO33-)
chromium(III) or chromic (Cr3+)
Group 7A anions - nitride (N3-), phosphide (P3-)
3+
iron(III) or ferric (Fe )
Group 3A cations - aluminum (Al3+)
+4 Charge
lead(IV) or plumbic (Pb4+)
tin(IV) or stannic (Sn4+)
Summary of metal cations with more than one possible charge:
Cu+, Cu2+; Hg22+, Hg2+; Fe2+, Fe3+; Pb2+, Pb4+; Sn2+, Sn4+
There are other metals that form more than two stable ions. These include manganese, chromium, cobalt, vanadium, and others.
You should know these four require Roman numerals.
Covalent compounds follow a different naming system
Binary covalent compounds use prefixes to indicate number of each atom.
Mono is not used if there is only one of the first atom; -ide is used as a suffix on the root of the second atom.
Number
Prefix
Number
Prefix
1
mono
6
hexa
2
di
7
hepta
3
tri
8
octa
4
tetra
9
nona
5
penta
10
deca
Binary acid (HnX) solutions form when certain gaseous compounds dissolve in water.
Ex. HCl gas dissolves in water to form hydrochloric acid.
hydro- + anion nonmetal root + -ic acid
- hydrochloric acid
Ex. HF HBr HI H2S -
hydrofluoric acid
hydrobromic acid
hydroiodic acid
hydrosulfuric acid