Give reasons for the following observation. The smell of hot sizzling food reaches you several metres away, But to get the small from cold food you have to go close. Why?

Answer: The smell of hot sizzling food can reach you from several metres away, but the smell of cold food requires you to get closer because particles of hot sizzling food have high kinetic energy and can diffuse in air quickly, reaching you from several metres away, whereas particles of cold food have low kinetic energy and cannot reach you from several metres away.

Matter particles have kinetic energy and are always in motion. Particles have less kinetic energy at lower temperatures and hence travel slowly. Cold food particles have little kinetic energy due to the low temperatures. Particles with high kinetic energy travel quicker at increasing temperatures, therefore heated vapours from hot meals move faster as well