Homogeneous and heterogeneous mixtures settle, or separate. As a homogeneous mixture, a solution has one phase (liquid) although the solute and solvent can vary: for example, salt water. Air can be more specifically described as a gaseous solution (oxygen and other gases dissolved in the major component, nitrogen). Since interactions between molecules play almost no role, dilute gases form rather trivial solutions. In part of the literature, they are not even classified as solutions. In gas intermolecular space is greatest and intermolecular force of attraction is least. In chemistry, a mixture is a substance containing two or more elements or compounds that are not
Chemistry: A Volatile History of a flame – this led Cavendish to name the gas inflammable air, which he believed to be one and the same as phlogiston. Cavendish, though he did not realise it, made an important observation about burning phlogiston in air; a dewy liquid was formed on the inside of the glassware: water. This should have had enormous repercussions for the whole scientific community in the 1700s, who still believed water to be an elemental substance. Yet, if water could be "made" by burning inflammable air, then water is "not" an element, but a compound. However, it simply did not occur