Salts are formed by the reaction of acids and base. And a salt contains positive and negative radicals both. On the basis of positive and negative radicals, salts can be categorized into family.If two salts have same positive or negative radicals, they are called to be of same family.In other words, if salts formed by the reaction of same acid with different bases, then all salts so formed belong to the same family. On the other hand if salts formed by the reaction same base with different acids, then all salts so formed have same negative radicals, and all such salts are called to be belonged to the same family.Example:In Sodium chloride and sodium sulphate, sodium which is positive radical is same in both of the salts. Thus, sodium chloride and sodium sulphate belongs to the sodium family.Similarly, in sodium chloride and potassium chloride, chloride which is negative radical is same. Thus, sodium chloride and potassium chloride both belong to chloride family.All salts having sulphate ions as negative radical belong to the sulphate family. For example: sodium sulphate, potassium sulphate, magnesium sulphate, aluminium sulphate, copper sulphate, etc.