What is the difference between an anion and a cation?

A cation is a positively charged ion formed when an atom loses electrons (usually metals). An anion is a negatively charged ion formed when an atom gains electrons (usually non-metals).

What is the difference between -ide, -ite, and -ate suffixes in chemistry?

The suffix '-ide' is used for monatomic anions (e.g., Chloride, Cl-). The suffixes '-ite' and '-ate' are used for polyatomic oxyanions. '-ate' has more oxygen atoms (e.g., Sulfate, SO4 2-), while '-ite' has fewer oxygen atoms (e.g., Sulfite, SO3 2-).

What are polyatomic ions?

Polyatomic ions are electrically charged groups of covalently bonded atoms that act as a single unit in chemical reactions (e.g., Ammonium NH4+, Nitrate NO3-).

Master chemical nomenclature! Here is the ultimate, organized list of the 100 most common Cations (+), Anions (-), and Complex Ions required for JEE, NEET, and Class 11/12 Chemistry.

100 Most Common Cations & Anions in Chemistry

Writing accurate chemical formulas and balancing equations is impossible without memorizing the charges of common ions. Ions are atoms or molecules that have gained or lost electrons, resulting in a net electrical charge.

In this comprehensive guide, we have categorized the 100 most important cations and anions you will encounter in Inorganic and Physical Chemistry. Bookmark this page as your ultimate reference sheet!

📄 Download Formula Sheets 📙 Inorganic Chemistry Notes 📇 Flashcard Tool

🔹 Section 1: Common Cations (Positive Ions)

Cations are positively charged ions formed when an atom (usually a metal) loses one or more electrons.

1. Monatomic Cations (Metals & Hydrogen)

No.	Formula	Ion Name	Charge
1	H⁺	Hydrogen ion / Proton	+1
2	Li⁺	Lithium	+1
3	Na⁺	Sodium	+1
4	K⁺	Potassium	+1
5	Rb⁺	Rubidium	+1
6	Cs⁺	Cesium	+1
7	Be²⁺	Beryllium	+2
8	Mg²⁺	Magnesium	+2
9	Ca²⁺	Calcium	+2
10	Sr²⁺	Strontium	+2
11	Ba²⁺	Barium	+2
12	Al³⁺	Aluminium	+3
13	Zn²⁺	Zinc	+2
14	Cd²⁺	Cadmium	+2
15	Ag⁺	Silver	+1
16	Cu⁺	Copper (I) / Cuprous	+1
17	Cu²⁺	Copper (II) / Cupric	+2
18	Fe²⁺	Iron (II) / Ferrous	+2
19	Fe³⁺	Iron (III) / Ferric	+3
20	Pb²⁺	Lead (II) / Plumbous	+2
21	Pb⁴⁺	Lead (IV) / Plumbic	+4
22	Sn²⁺	Tin (II) / Stannous	+2
23	Sn⁴⁺	Tin (IV) / Stannic	+4
24	Ni²⁺	Nickel (II)	+2
25	Co²⁺	Cobalt (II)	+2
26	Co³⁺	Cobalt (III)	+3
27	Mn²⁺	Manganese (II)	+2
28	Mn³⁺	Manganese (III)	+3
29	Cr²⁺	Chromium (II)	+2
30	Cr³⁺	Chromium (III)	+3
31	Hg₂²⁺	Mercury (I) / Mercurous	+1 (per Hg)
32	Hg²⁺	Mercury (II) / Mercuric	+2

2. Polyatomic Cations

No.	Formula	Ion Name	Charge
33	NH₄⁺	Ammonium	+1
34	H₃O⁺	Hydronium	+1

🔹 Section 2: Common Anions (Negative Ions)

Anions are negatively charged ions formed when an atom (usually a non-metal) or a molecule gains one or more electrons.

3. Monatomic Anions (Non-metals)

No.	Formula	Ion Name	Charge
35	H^-	Hydride	-1
36	F^-	Fluoride	-1
37	Cl^-	Chloride	-1
38	Br^-	Bromide	-1
39	I^-	Iodide	-1
40	O^2-	Oxide	-2
41	O₂^2-	Peroxide	-2
42	S^2-	Sulfide	-2
43	Se^2-	Selenide	-2
44	N^3-	Nitride	-3
45	P^3-	Phosphide	-3
46	C^4-	Carbide	-4

4. Polyatomic Oxyanions & Others

No.	Formula	Ion Name	Charge
47	OH^-	Hydroxide	-1
48	CN^-	Cyanide	-1
49	NO₂^-	Nitrite	-1
50	NO₃^-	Nitrate	-1
51	CO₃^2-	Carbonate	-2
52	HCO₃^-	Bicarbonate / Hydrogen carbonate	-1
53	SO₃^2-	Sulfite	-2
54	SO₄^2-	Sulfate	-2
55	HSO₄^-	Bisulfate / Hydrogen sulfate	-1
56	S₂O₃^2-	Thiosulfate	-2
57	ClO^-	Hypochlorite	-1
58	ClO₂^-	Chlorite	-1
59	ClO₃^-	Chlorate	-1
60	ClO₄^-	Perchlorate	-1
61	BrO₃^-	Bromate	-1
62	IO₃^-	Iodate	-1
63	MnO₄^-	Permanganate	-1
64	CrO₄^2-	Chromate	-2
65	Cr₂O₇^2-	Dichromate	-2
66	PO₄^3-	Phosphate	-3
67	HPO₄^2-	Hydrogen phosphate	-2
68	H₂PO₄^-	Dihydrogen phosphate	-1
69	BO₃^3-	Borate	-3
70	SiO₃^2-	Silicate	-2
71	C₂O₄^2-	Oxalate	-2
72	SCN^-	Thiocyanate	-1
73	OCN^-	Cyanate	-1
74	HSO₃^-	Bisulfite / Hydrogen sulfite	-1

5. Organic Anions

No.	Formula	Ion Name	Charge
75	CH₃COO^-	Acetate	-1
76	C₆H₅COO^-	Benzoate	-1
77	C₂H₅COO^-	Propionate	-1
78	HCOO^-	Formate	-1
79	C₆H₅O^-	Phenoxide	-1
80	C₃H₅O₃^-	Lactate	-1
81	C₄H₅O₆^2-	Tartrate	-2
82	C₆H₅SO₃^-	Benzenesulfonate	-1

🔹 Section 3: Complex & Coordination Ions

These complex ions (both cations and anions) frequently appear in Coordination Chemistry and qualitative analysis.

No.	Formula	Ion Name	Charge
83	AlO₂^-	Aluminate	-1
84	ZnO₂^2-	Zincate	-2
85	FeO₄^2-	Ferrate	-2
86	CoO₄^2-	Cobaltate	-2
87	Ni(CO)₄^2-	Tetracarbonyl nickelate	-2
88	[Fe(CN)₆]^3-	Ferricyanide / Hexacyanoferrate (III)	-3
89	[Fe(CN)₆]^4-	Ferrocyanide / Hexacyanoferrate (II)	-4
90	[Cu(NH₃)₄]²⁺	Tetraammine copper (II)	+2
91	[Ag(NH₃)₂]⁺	Diamminesilver (I)	+1
92	[Zn(NH₃)₄]²⁺	Tetraamminezinc (II)	+2
93	[Co(NH₃)₆]³⁺	Hexaamminecobalt (III)	+3
94	[Cr(H₂O)₆]³⁺	Hexaaquachromium (III)	+3
95	[Ni(CN)₄]^2-	Tetracyanonickelate (II)	-2
96	[Cu(CN)₄]^3-	Tetracyanocuprate (I)	-3
97	[Ag(CN)₂]^-	Dicyanoargentate (I)	-1
98	[PtCl₆]^2-	Hexachloroplatinate (IV)	-2
99	[AuCl₄]^-	Tetrachloroaurate (III)	-1
100	[MnO₄]^2-	Manganate	-2

Nomenclature Rules: -ide, -ite, and -ate

Struggling to remember which is which? Follow these simple rules for naming anions:

-ide: Usually indicates a simple monatomic anion (e.g., Cl^- is Chloride, O^2- is Oxide). Exception: Hydroxide (OH^-) and Cyanide (CN^-).
-ate: Indicates the polyatomic oxyanion with the most common number of oxygen atoms (e.g., SO₄^2- is Sulfate).
-ite: Indicates a polyatomic oxyanion with exactly one less oxygen atom than the "-ate" form, but with the same charge (e.g., SO₃^2- is Sulfite).
Hypo- / Per-: "Hypo-" means one less oxygen than "-ite" (e.g., ClO^- is Hypochlorite). "Per-" means one more oxygen than "-ate" (e.g., ClO₄^- is Perchlorate).

Frequently Asked Questions (FAQs)

How do I write a chemical formula using these ions?

Use the "Criss-Cross Method". Write the cation symbol and its charge, then the anion symbol and its charge. Cross the magnitude of the charges (just the numbers, drop the + or -) to become the subscripts of the opposite ion. Ensure the final ratio is simplified. (Example: Al³⁺ and O^2- become Al₂O₃).

What is the difference between Ferrous and Ferric?

Metals with variable oxidation states use suffixes to indicate their charge. -ous indicates the lower charge, while -ic indicates the higher charge. Therefore, Ferrous is Fe²⁺ and Ferric is Fe³⁺.

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