The mass per unit volume of a substance is called density. (density =mass/volume). Arrange the following in order of increasing density-air, exhaust. From chimneys, honey, wter,chalk,cotton and iron.

Explanation

Since the density `="mass"//"volume"`, this means that the density of a substance is directly proportional to the mass as well as number of particles and is inversely proportional to the inter-particle spaces or volume. In the presnet case, both air and exhaust from chimneys are gases. However, air is a mixture of number of gases in which the main constituents are nitrogen and oxygen but exhaust from chimneys are also contaminated with carbon and fumes of posonous gases such as sulphur dioxide, oxides of nitrogen etc. Thus, the density of exhaust from chimneys is more. Both honey and water are liquids. Since honey is thick as compared to water, its density is more. Since iron is heavier than chalk, its density is more. Cotton no doubt, is a solid. But it is extremely porous and the pores are filled by air. This is therefore, very light. Air `lt` exhaust from chimneys `lt` cotten `lt` water `lt` honey `lt` chalk `lt` iron.