The state's landlord-tenant laws protect people living in dwellings owned or leased by others. A person need not be listed on a formal lease to gain protection under these laws, but may gain protection by establishing residence in a place.
The mole is useful in chemistry because it is defined such that the mass of Avogadro's number of particles (atoms or molecules) of a substance (the molar mass) is equal to the sum of the numerical values of the atomic masses of its constituent elements.
Mole fraction describes the number of molecules (or moles) of one component divided by total the number of molecules (or moles) in the mixture. Mole fraction is useful when two reactive components are mixed together, as the ratio of the two components is known if the mole fraction of each is known.