Name and Formula of Cations Introductory Chemistry Tutorial
- A cation is a positively charged ion.
- A cation can be composed of:
⚛ one atom (monoatamic cation)
⚛ more than one atom (polyatomic cation)
- The formula of a monoatomic(1) cation is made up of two parts:
Formula of Monoatomic Cation symbol of element charge as a superscript(2) to the right of the symbol E x+
Note the charge on the cation is given with the number first followed by the plus sign.
Ex+ NOT E+x
- The name of a monoatamic cation is made up of two parts:
Systematic IUPAC Name of Monoatomic Cation name of element (charge in parentheses given to the right of the name) element (x+)
Note there is no space between the name of the element and the parentheses.
element(x+) NOT element (x+)
- The cation of the element hydrogen can be named systematically as above, but it also has an acceptable non-systematic name:
Naming H+ systematic IUPAC name hydrogen(1+) acceptable non-systematic IUPAC name hydron name in common use but not preferred proton (3)
- You will be expected to know the name and formula of some polyatomic cations:
Name and Formula of Some Polyatomic Cations formula IUPAC Name Systematic Acceptable Non-systematic NH4+ azanium (4) ammonium H3O+ oxidanium oxonium (5) Hg22+ dimercury(2+) (6)