Answer:
Coefficient of
is more than 4
Explanation:
Oxidation: 
- Balance charge:
......(1)
Reduction: 
- Balance Cr:

- Balance O and H in acidic medium:

- Balance charge:
.......(2)
gives balanced equation:

So coefficient of
is more than 4
Answer: Option (d) is the correct answer.
Explanation:
Endothermic process is a process in which energy or heat is absorbed by reactant species.
For example, melting of ice cubes is an endothermic process as it is absorbing heat from the surrounding and gives a cooling effect.
Thus, we can conclude that the process in which a substance gains energy is an endothermic process.
Answer: it's c. Axial precession
Explanation:
First you have to tell people what are the choices