What is the process of converting a solid directly into a gaseous state called?

What are the fundamental components of matter?

According to Dalton's atomic theory,the smallest particle in which matter can exist,is called

The separation of two coloured substances was done by paper chromatography. The distances travelled by solvent front,substance $A$ and substance $B$ from the base line are $3.25 \ cm$,$2.08 \ cm$ and $1.05 \ cm$ respectively. The ratio of $R_{f}$ values of $A$ to $B$ is $.........$

Explain the concept of a compound.

$A$ miscible mixture of $C_6H_6 + CHCl_3$ can be separated by