Questions

The answer is EDUCATION

4,5,6 make up the word cat,

7th is 'i' which means me,

3rd letter is 'u' which mean you,

2,8,9,1 make up the word done, which means completed

and nobody can read without education.

In chemistry rusting is called as oxidation. Oxidation is a chemical process where metal gains oxygen and become oxide. In rusting the Iron ore make a chemical reaction with the oxygen in the presence of water and environmental or atmospheric moisture to produce an Iron oxide. Iron oxide is otherwise called as rust.

The rusting of iron is a chemical change because it is two substances reacting together to make a new substance. 

Rusting would only be a physical change if iron molecules remained pure iron throughout the process.

The stratosphere layer of the atmosphere is very dry.

Tin and Silver are malleable and good conductors of electricity. The other combinations have a non metal in them which are bad conductors.

Hypnology is the study of sleep.