Question

Identify the physical and chemical changes from the following phenomena: 

1. Transformation of ice into water. 
2. Ripening of fruit. 
3. Milk turned into curd. 
4. Evaporation of water. 
5. Digestion of food in the stomach. 
6. Iron filings get attracted towards the magnet. 

Hint:

In physical changes, no new substances are formed, and the changes are typically reversible. In chemical changes, new substances are formed, and the process is often irreversible.

Answer 1

1. Transformation of ice into water:
      This is a physical change because the substance (H2O) remains the same; only its state changes from solid to liquid.
      
2. Ripening of fruit:
      This is a chemical change because new substances, such as sugars and acids, are formed as the fruit ripens.
      
3. Milk turned into curd:
      This is a chemical change because it involves a biochemical process where bacteria ferment milk, converting lactose into lactic acid, which leads to the formation of curd.
      
4. Evaporation of water:
      This is a physical change because the water only changes from liquid to gas without altering its chemical composition.
      
5. Digestion of food in the stomach:
      This is a chemical change because food undergoes chemical reactions like hydrolysis, breaking down into simpler compounds.
      
6. Iron filings get attracted towards the magnet:
      This is a physical change because it only changes the magnetic properties of the iron filings, not their chemical structure.