Describe two changes that are harmful. Explain why you consider them harmful .How can you prevent them ?
Rusting of iron and Burning of wood are to harmful changes.
Rusting of iron:
Every year, our world suffers huge monetary losses owing to the process of rusting, which causes harm to the articles made of iron.
Prevention:Painting or coating iron articles with grease: This does not allow iron to come in contact with oxygen and water. Hence, it prevents rusting. In fact, paints and grease should be applied regularly to prevent rusting.
Burning of wood:
Burning of wood produces large amount of harmful gases that pollute our environment and cause Green House Effect ( rise in temperature of earth).
Prevention: Use of cleaner fuel like LPG,CNG and Bio-fuel etc.