Atom is the basic unit of life
It comprises every living and non-living thing.
These are the smallest particles that makes everything we see, hear, senese, smell, and touch.
The gas law involving constant pressure would be Avogrados Law where in under conditions of constant pressure and temperature, there is a direct relationship between the number of moles and volume of a gas.
So your answer is
Examples of aromatic Hydrocarbons are Toluene, benzene, naphthalene, anthracene,Toluene .
Hope this helps you