An ion is an atom or group of atoms where the number of electrons is not equal to the number of protons. When an atom loses or gains electrons, a positive or negative charge is the result. If electrons are gained, the ion is a cation and when electrons are lost, it is an anion.
Some Positive Ions
Many common materials that you may be familiar with can be considered ions.
Here are examples of cations, or positive, ions:
- Aluminum - Al+3
- Ammonium - NH4+1
- Barium - Ba+2
- Bismuth - Bi3+
- Cadmium - Cd2+
- Calcium - Ca+2
- Cesium - Cs+
- Chromium (III) - Cr+3
- Cobalt - Co+2
- Copper (I) - Cu+1
- Copper (II) - Cu+2
- Hydrogen - H+1
- Iron (II) - Fe+2
- Iron (III) - Fe+3
- Lead (II) - Pb+2
- Lithium - Li+1
- Magnesium - Mg+2
- Mercury (I) - Hg2+2
- Mercury (II) - Hg+2
- Nickel - Ni+2
- Potassium - K+1
- Rubidium - Rb+
- Silver - Ag+1
- Sodium - Na+1
- Strontium - Sr+2
- Tin (II) - Sn+2
- Zinc - Zn+2
As you can see, these ions are commonly found.
- Sodium is another name for table salt, for example, which you may have on your dinner table.
- Mercury is found in thermometers.
- Aluminum is a metal that is found in a surprising amount of things (You may find, for example, that aluminum is even an ingredient in baking soda and in certain other food products.).
These ions are everywhere.
Some Negative Ions
Here are examples of anions, or negative, ions:
- Acetate - C2H3O2-1
- Bicarbonate - HCO3-1
- Bromide - Br-1
- Carbonate - CO3-2
- Chlorate - ClO3-1
- Chloride - Cl-1
- Chromate - CrO4-2
- Dichromate - Cr2O7-2
- Dihydrogen phosphate - H2PO4-1
- Fluoride - F-1
- Hydrogen phosphate - HPO4-2
- Hydrogen sulfate - HSO4-1
- Hydroxide - OH-1
- Iodide - I-1
- Nitrate - NO3-1
- Nitride - N-3
- Nitrite - NO2-1
- Oxide - O-2
- Permanganate - MnO4-1
- Peroxide - O2-2
- Phosphate - PO4-3
- Sulfate - SO4-2
- Sulfide - S-2
- Sulfite - SO3-2
- Thiocyanate - SCN-1
- Thiosulfate - S2O3
Again, some of these ions you may be familiar with. Flouride, for example, is sometimes added to community water supplies. Your dentist may also give you a flouride treatment.
Polyatomic Cations and Anions
If an ion has two or more atoms it is called a polyatomic ion.
Here are examples of polyatomic cations and anions:
Polyatomic Cations
- Ammonium - NH4+
- Hydronium - H3O+
Polyatomic Anions
- Acetate - CH3COO or C2H3O2-
- Arsenate - AsO4 3-
- Borate - BO3 3-
- Carbonate - CO3 2-
- Chlorate - ClO3-
- Chlorite - ClO2-
- Chromate - CrO4 2-
- Cyanide CN-
- Dichromate - Cr2O7 2-
- Dihydrogen phosphate - H2PO4-
- Formate - CHO2-
- Hydrogen carbonate or bicarbonate - HCO3-
- Hydrogen sulfate or bisulfate - HSO4-
- Hydrogen sulfite or bisulfite - HSO3-
- Hydrogen phosphate - HPO4 2-
- Hydroxide OH-
- Hypochlorite - ClO-
- Nitrate - NO3-
- Nitrite - NO2-
- Oxalate - C2O4 2-
- Perchlorate - ClO4-
- Permanganate - MnO4-
- Peroxide O2 2-
- Phosphate - PO4 3-
- Phosphite - PO3 3-
- Silicate - SiO3 2-
- Sulfate - SO4 2-
- Sulfite - SO3 2-
- Thiosulfate - S2O3 2-
Ionic Compounds
An ionic compound is made up of one or more anions and one or more cations.
Here are some examples:
- Aluminum sulfide - Al2S3
- Beryllium chloride - BeCl2
- Boron iodide - BI3
- Calcium nitride - Ca3N2
- Copper phosphide - Cu3P
- Iron (II) iodide - FeI2
- Iron (III) oxide - Fe2O3
- Lead (II) sulfide - PbS
- Lead (IV) phoshide - Pb3P4
- Lithium fluoride - LiF
- Magnesium chloride - MgCl2
- Potassium bromide - KBr
- Sodium fluoride - NaF
- Sodium nitride - Na3N
When you study chemistry, you will encounter many examples of ions as well as information about many of these different types of ions and about how these ions interact and relate to each other.
Do you have a good example to share? Add your example here.
comments powered by DisqusIon Examples
By YourDictionary
An ion is an atom or group of atoms where the number of electrons is not equal to the number of protons. When an atom loses or gains electrons, a positive or negative charge is the result. If electrons are gained, the ion is a cation and when electrons are lost, it is an anion.
