'Sun' as a natural factor helps in the formation of soil. Explain,how.

(N/A) $(i)$ The sun heats up the rocks during the day,causing them to expand.
$(ii)$ At night,the rocks cool down and contract.
$(iii)$ Since different parts of the rock expand and contract at different rates,this unequal stress causes the rocks to crack and break into smaller pieces over time,eventually forming soil.