(a) Describe an activity to show that while the paper is biodegradable but plastic (say, polythene) is non-biodegradable. (b) Explain why some materials are biodegradable but some are non-biodegradable.

(a) An activity to prove that paper is biodegradable and plastic is non-biodegradable is described below.

Take a piece of paper and a polythene bag. Burry these two items separately in soil about 15cm deep. After a month when you relook on digging you will notice that the paper is completely decomposed by bacteria but the polythene bag is the same. This shows that paper is decomposed and is biodegradable and plastic is non-biodegradable.

(b) Some materials are biodegradable, whereas some are non-biodegradable because decomposers break down natural materials but do not break down man-made materials such as plastics as they are made up of complex materials and they are not specific in their action on non–biodegradable waste.