Argon is inter gas .why?​

Argon--along with helium, neon, xenon, radon, and krypton--belongs to the so-called "noble" gases. ... Also called inert gases, they have complete outer electron shells and were believed not to react with other elements or compounds.

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume