Why are Si and GaAs are preferred materials for solar cells?

The material used in the solar cells contains

Why cotton dress is preferred in summer?

What are detergents? How are they classified? Why are detergents usually preferred to soaps for washing clothes? Give an example of detergents.

Two wires of equal length, one of copper and the other of aluminium have the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are prefered for overhead power cables. (P_(Al) = 2.63 xx 10^(-8) Omega m , P_(Cu) = 1.72 xx 10^(-8) Omega m , Relative density of Al = 2.7 , of Cu = 8.9.

Why is dihydrogen gas not preferred in balloons?

Why complexes are preferred in the electrolytic bath for electroplating?

Both RNA and DNA are considered as genetic materials. Why DNA is considered as a better genetic material than RNA?