Which common cations should I memorise?

Memorise alkali (Li+, Na+, K+, Rb+, Cs+), alkaline earth (Mg2+, Ca2+, Sr2+, Ba2+) and common transition cations (Fe2+/3+, Cu+/2+, Zn2+).

What are key polyatomic anions to know?

NO2-, NO3-, SO3 2-, SO4 2-, CO3 2-, PO4 3-, HCO3-, MnO4-, CrO4 2-, Cr2O7 2- are frequently asked.

Quick tip to remember charges?

Know groups: alkali +1, alkaline earth +2, halides -1, many polyatomics have fixed charges — make flashcards.

names of ions important for NEET and JEE

This article lists the names of ions important for NEET and JEE in simple, exam-friendly format. Below you get organised cation and anion tables, common polyatomic ions and a quick interactive JS quiz to test yourself at the end.

Cations — common names by charge

Memorise these names and common alternative names (ous/ic endings for some metals are older naming systems you may see in questions).

+1 Cations (Monovalent)

Common +1 cations and names
Ion	Name	Notes / Alternate names
H⁺	Hydrogen (proton)	Acid species
Li⁺	Lithium	Alkali metal
Na⁺	Sodium	Biological electrolyte
K⁺	Potassium	Major intracellular cation
Rb⁺	Rubidium	Less common in questions
Cs⁺	Cesium	Alkali metal
Cu⁺	Cuprous	Less stable than Cu²⁺
Hg⁺	Mercurous	Older naming (Hg₂²⁺)
Ag⁺	Argentous / Silver(I)	Precipitates with Cl^-
Au⁺	Aurous	Gold(I)
NH₄⁺	Ammonium	Common polyatomic cation

+2 Cations (Divalent)

Common +2 cations and names
Ion	Name	Notes / Alternate names
Mg²⁺	Magnesium	Chlorophyll central metal
Ca²⁺	Calcium	Bone/teeth, hardness
Sr²⁺	Strontium	Alkaline earth
Ba²⁺	Barium	Heavy alkaline earth
Zn²⁺	Zinc	Enzyme cofactor
Cu²⁺	Cupric	Blue/green salts
Hg²⁺	Mercuric	Toxic metal
Ag²⁺	Argentic	Less common
Pb²⁺	Plumbous	Lead(II)
Sn²⁺	Stannous	Tin(II)

+3 Cations (Trivalent)

Common +3 cations and names
Ion	Name	Notes / Alternate names
Al³⁺	Aluminium	Amphoteric oxide
Ga³⁺	Gallium	Less common
Fe³⁺	Ferric	Iron(III), red-brown salts
Au³⁺	Auric	Gold(III)
Ag²⁺	Argentic	Rare

+4 Cations (Tetravalent)

Common +4 cations and names
Ion	Name	Notes / Alternate names
Fe²⁺	Ferrous (note: Fe2+ is actually +2)	Included above for clarity
Pb⁴⁺	Plumbic	Lead(IV)
Sn⁴⁺	Stannic	Tin(IV)

Anions — common names by negative charge

Listed below are monoatomic and some polyatomic anions grouped by charge.

-1 Anions (Monovalent)

Common -1 anions and names
Ion	Name	Notes
H^-	Hydride	Found in metal hydrides
D^-	Deuteride	Isotopic analogue
F^-	Fluoride	Halide
Cl^-	Chloride	Halide; AgCl precipitate
Br^-	Bromide	Halide
I^-	Iodide	Halide
OH^-	Hydroxide	Base
SH^-	Bisulphide (hydrosulphide)	Often written HS^-
NH₂^-	Amide	Strong base
CN^-	Cyanide	Toxic; strong ligand
NC^-	IsoCyanide	Isomer of CN^-
SCN^-	Thiocyanate	Ligand in coordination chemistry
NO₂^-	Nitrite	Oxidation state +3 for N
NO₃^-	Nitrate	Common oxidant in salts
HCOO^-	Formate	Carboxylate
CH₃COO^-	Acetate	Carboxylate
ClO^-	Hypochlorite	Bleach species
ClO₂^-	Chlorite	Oxidiser
ClO₃^-	Chlorate	Oxidiser
ClO₄^-	Perchlorate	Strong oxidiser
O₂^-	Superoxide	Reactive oxygen species
O₃^-	Ozonide	Rare, reactive
BO₂^-	Meta-borate	Boron oxyanion
AlO₂^-	Meta-aluminate	Aluminium oxyanion

-2 Anions (Divalent)

Common -2 anions and names
Ion	Name	Notes
O^2-	Oxide	Basic oxide
S^2-	Sulphide	Metal sulphides
SO₃^2-	Sulphite	Reduced sulphur oxyanion
SO₄^2-	Sulphate	Common anion; BaSO₄ test
S₂O₃^2-	Thiosulphate	Used in titrations, photography
CO₃^2-	Carbonate	Reacts with acid to give CO₂
C₂O₄^2-	Oxalate	Forms insoluble salts with Ca²⁺
ZnO₂^2-	Zincate	Complex anion
PbO₂^2-	Plumbite	Lead oxyanion (various forms)
PbO₃^2-	Plumbate	Lead oxyanion
CrO₄^2-	Chromate	Yellow; pH-dependent with dichromate
Cr₂O₇^2-	Dichromate	Orange; strong oxidiser
SiO₃^2-	Silicate	Various structures
SiO₄^4-	Orthosilicate	See -4 anions
MnO₄^2-	Manganate	Reduced form of permanganate
PbO₂^2-	Plumbite (alternate)	See above

-3 Anions (Trivalent)

Common -3 anions and names
Ion	Name	Notes
N^3-	Nitride	Rare in aqueous chemistry
P^3-	Phosphide	Metal phosphides
PO₃^3-	Phosphite	Phosphorus oxyanion
PO₄^3-	Phosphate	Biologically important
BO₃^3-	Borate	Boron oxyanion
AsO₃^3-	Arsenite	Toxic oxyanion
AsO₄^3-	Arsenate	Toxic oxyanion
[Fe(CN)₆]^3-	Ferricyanide	Complex ion
NH₂^-	Imide	Also appears in organic chemistry

-4 Anions (Tetravalent and special)

Common -4 anions and names
Ion	Name	Notes
C^4-	Carbide	Very basic anion in solid-state chemistry
SiO₄^4-	Orthosilicate	Silicate family
[Fe(CN)₆]^4-	Ferrocyanide	Coordination complex
SnO₂^2-	Stannite (note: names vary)	Tin oxyanion
SnO₃^2-	Stannate	Tin oxyanion

Polyatomic & special ions (quick reference)

Useful polyatomic ions and a short name list taken from your notes.

NO₂^- — Nitrite
NO₃^- — Nitrate
HCO₃^- — Bicarbonate / Hydrogen carbonate
CO₃^2- — Carbonate
SO₃^2- — Sulphite
SO₄^2- — Sulphate
PO₄^3- — Phosphate
S₂O₃^2- — Thiosulphate
MnO₄^- — Permanganate
MnO₄^2- — Manganate
CrO₄^2- / Cr₂O₇^2- — Chromate / Dichromate
[Fe(CN)₆]^4-/3- — Ferrocyanide / Ferricyanide
CH₃COO^-, HCOO^- — Acetate, Formate

Mnemonics & quick memory tips

Alkali/Alkaline rule: Alkali metals = +1, Alkaline earth = +2.
Halide reminder: F, Cl, Br, I are all -1 (think "F C B I").
Oxyanion count: More oxygens → higher oxidation state of central atom (sulphate SO₄^2- vs sulphite SO₃^2-).
Old naming: "ous" = lower oxidation state (Fe2+ = ferrous), "ic" = higher (Fe3+ = ferric).

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Names of Ions Important for NEET and JEE | Complete List with Quiz

names of ions important for NEET and JEE