Give reason :
1. Iron objects are galvanised (coated with a layer of zir
2. Germination of seed is a chemical change.
3. Rusting takes place faster near a sea coast.
4. Melting of snow is a physical change.
5. Photosynthesis in plants is a chemical change.
Answers
Answer:
1. Galvanization is the method of coating iron with zinc to prevent rusting. ... Zinc prevents the formation of layer of oxide on the iron which in the presence of air and water leads to rust formation.
2. Germination of seed is a chemical change because a seed has developed into a complete plant which is permanent and irreversible. Germination of seed is a chemical change because the original seed can never be re-gained back from the plant it grows into.
3. Rusting of iron occurs only if iron comes in contact with moist air. In coastal areas, air contains high percentage of moisture because of sea or ocean, while in deserts air is dry and hot. As the percentage of moisture in air is more in coastal area compared to desert, rusting becomes faster.
4. In melting process of snow or any other material, there is no chemical reaction and changes, therefore, it is only a physical phenomenon. ... Because the process is reversible without need to any chemical reaction; molten snow can turn back to snow.
5. Photosynthesis is the process through which plants convert light energy into chemical energy. Here is the chemical reaction involved: water and carbon dioxide combine to form glucose and oxygen. Since new chemical species are formed, photosynthesis is clearly a chemical change.