1. Why does cut apple turn brown when
exposed to air ?
2. Why does old car bumper change colour?
3. Why do new batteries become useless
after some days ?
Answers
Answer:
1 When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products.
2As a car gets old, the color of its bumper slowly starts to fade due to evaporation. Explanation: Bumpers are either made up of metal or of plastic. However, both these kinds of material are subjected to evaporation that causes the fade in color of the bumper.
3In a healthy battery, ions flow freely between a cathode and an anode. Charging a battery forces ions from the cathode to the anode; using the battery reverses the flow. Over time, this process wears out the cathode, which results in reduced capacity.
Explanation:
hope it helps you
Answer:
1 When an apple is cut (or bruised), oxygen is introduced into the injured plant tissue. When oxygen is present in cells, polyphenol oxidase (PPO) enzymes in the chloroplasts rapidly oxidize phenolic compounds naturally present in the apple tissues to o-quinones, colorless precursors to brown-colored secondary products.