What are the main states of matter?

When the temperature is raised,the viscosity of a liquid decreases. This is because:

Two gases $A$ and $B$ having the same volume diffuse through a porous partition in $20$ and $10$ seconds respectively. The molecular mass of $A$ is $49 \ u$. The molecular mass of $B$ will be .............. $u$.

What is the order of intermolecular forces in solids,liquids,and gases?

Write the formula to calculate the pressure of a dry gas collected over water.

If two gases $CH_4$ and $SO_2$ are allowed to enter from the two ends of a $1 \ km$ long vacuum tube at the same time,where will the gases meet from the $CH_4$ end (in $m$)?