Question

what happens when
1. a fresh cut apple left open in air
2. ice melts
3. milk is left at room temperature during summer
4. an iron nail is exposed to humid atmosphere
5. food gets digested in our body
6. we inhale carbon-monoxide​

Answer 1

1. When an apple is cut open, an enzyme called polyphenol oxidase is released from the cells of the apple and reacts with the oxygen in the air. ... However, once the ascorbic acid gets used up, the oxygen will start reacting with the enzyme and browning will occur. 

2. The water level remains the same when the ice cube melts. 

3. When the milk is left at room temperature during summer season the oxidation reaction occurs and the growth ofmicroorganisms occur due to which it gets sour.

4. Oxygen present in the atmospherereacts with the iron in the presence of moisture or water vapour to form a reddish brown coating called ironoxide or rust when an iron object is leftexposed to humid atmosphere

5. The stomach produces acid that helps to kill bacteria and other germs that may get into food.It then pushes the small particles of food into the first part of the small intestine, called the duodenum. The small intestine is where most of the digestion and absorption of our food takes place