Questions

We require vitamins B & C for hair growth. But Vitamin B such as Vitamin B7 or Biotin is required for the growth of hair.

A modem is a hardware device which performs both modulation and demodulation. MODEM means (Modulator-Demodulator).

Burning gasoline is the only process that involving in a chemical change in the given options. A chemical change is a change in the starting substances that are called reactants from the formed new substances that are called products. 

Due to the molecules present in the 2,2-dimethylbutane are closely packed, it has the highest boiling point.

The processes both osmosis and diffusion come under passive transport and require no energy. The movement of solute from the region of higher concentration to the region of lower concentration is nothing but diffusion.