Our Environment | Activities in Text Book with Solution
Activity 15.5
Collect waste material from your homes. This could include all the waste generated during a day, like kitchen waste (spoilt food, vegetable peels, used tea leaves, milk packets and empty cartons), waste paper, empty medicine bottles/strips/bubble packs, old and torn clothes and broken footwear.
Bury this material in a pit in the school garden or if there is no space available, you can collect the material in an old bucket/flower pot and cover with at least 15 cm of soil.
Keep this material moist and observe at 15-day intervals.
What are the materials that remain unchanged over long periods of time?
✅ Answer:
Milk packets, medicine bottles, strips, plastic covers etc.
Substances that are not broken down by biological processes are called non-biodegradable. They are inert and persist for a long time or may harm the ecosystem. E.g. Plastics, glass, nylon etc.
What are the materials which change their form and structure over time?
Of these materials that are changed, which ones change the fastest?
✅ Answer:
Spoilt food, vegetable peels, used tea leaves, empty cartons, waste paper, old and torn clothes etc. are changed over time.
Substances that are
broken down by biological processes are called biodegradable. E.g.
Fruits, vegetables, leaves, meat, paper, rubber etc.
Spoilt food, vegetable peels etc. undergo fastest changes.