CBSE Class 9 Answered

Zeolites consist of silicon, aluminium, oxygen and metal ions (sodium, calcium, potassium) in a structure like hollow cages.

Inside these cages are exposed negative charges which give zeolites unique properties.

They have vast internal surface areas; a 1mm block has an internal area equivalent to several football fields.

The charge and open spaces allow them to be used for ion exchangers and pollution traps for contaminant molecules.

Most commonly they are used in deter-gents and as catalysts in the refining of petroleum.

Different Zeolite minerals have fifferent sized cage openings and can therefore filter out or absorb different sized molecules. Not all zeolites are the same.