The answer
Entropy increases because nature tends toward maximum disorder. In class 11, think of it as a statistical probability: there are more ways to arrange particles in a disordered state than in an ordered one. For a spontaneous process, total entropy (system + surroundings) always increases (ΔS_univ > 0). This is the second law of thermodynamics. For example, gas expanding into a vacuum increases entropy because molecules spread out. Even if a system becomes ordered, the surroundings get more disordered, so overall entropy rises. Exam tip: remember ΔS = q_rev/T and that entropy is a state function. So, just remember: more chaos, more entropy.
