Rajesh cut the apple, after sometime he observed brown colour on the apple pieces.
Predict the reason.

Dheeraj observed that the colour of walls of his house changes gradually into shiny white after white wash. He asked you, why did the colour changed into bright white. Predict the reason.

Why does cut apple turn brown when exposed to air?

Why the apples, pears, bananas, etc. change their colour when they cut nd exposed to air?

On keeping iron nails in a blue coloured copper sulphate solution, it is observed that the colour of the solution turns light green after sometime. Give reasons for this colour change. Name the type of reaction.

A person got his finger cut, after sometime the bleeding is stooped. Find out the reasons and explain its process.