Roman numerals in chemical names, like in 'Iron(III) oxide', are used to specify the exact positive charge of a metal ion that can have multiple different charges.
In chemistry, the suffix '-ite' on a polyatomic ion like nitrite (NO2-) means it has exactly one fewer oxygen atom than its '-ate' counterpart, nitrate (NO3-).
The common household cleaner 'washing soda' is actually a hydrate, meaning each molecule of the chemical sodium carbonate is attached to ten molecules of water.
In chemistry, the names of many simple compounds are created by keeping the metal's name and changing the end of the nonmetal's name to '-ide,' turning sodium and chlorine into 'sodium chloride'.
