An element crystallises in a bcc lattice with cell edge of 500 pm. The density of the element is $$7.5 \mathrm{~g} \mathrm{~cm}^{-3}$$. How many atoms are present in 300 g of metal?

Which among the following compound is not optically active?

Which of the following benzylic alcohol is tertiary alcohol?

Identify the hydrocarbon compound from following containing carbon atoms in the range of $$\mathrm{C}_6$$ to $$\mathrm{C}_8$$ ?