Newton's first law is the answer.
Explanation:
21. The given molecule for cracking is tetradecane.
On cracking it forms one mole of decane (C10H22) and two moles of ethene gas.
The chemical equation is shown below:

22. The essential condition for the formation of an ester is the reaction of alcohol and acid in presence of concentrated sulfuric acid.
Thus among the given options, the first option is the correct one.
23. Isomers of butanol are shown below:
It is 2-butanol.
The position of -OH group changes to the second carbon.
Answer:
5.72 g ( 1 mol / 180.16 g ) ( 6.022 x 10^23 molecules / mole ) = 1.90x10^23 molecules
Answer:
Particles of matter possess energy called kinetic energy.
Solid cannot be compressed, but gases are highly compressible.
The Kinetic energy of molecules of gases is very large & solids the least.
On heating a sublimable liquid, the molecules break free & escape from the surface of the solid directly into vapour.
Particles of matter move more rapidly on the application of heat