Give reasons [2] i) Gases do not settle at the bottom of the vessel. [1] ii) Deliquescent substances turns into liquid when exposed to atmospheric air. [1]

i) Gases do not settle at the bottom of the vessel Gases do not settle at the bottom of a vessel because their molecules are in continuous random motion due to high kinetic energy. This motion is rapid and chaotic, causing gas particles to collide with each other and the vessel walls. Unlike solids and liquids, gas molecules are far apart and experience negligible intermolecular forces, allowing them to uniformly distribute throughout the available space. This behavior is described by the kinetic molecular theory of gases, which states that gas particles move freely in all directions, filling the container’s volume.

ii) Deliquescent substances turn into liquid when exposed to atmospheric air Deliquescent substances (e.g., NaOH, CaCl₂, MgCl₂) absorb moisture from the atmosphere due to their strong affinity for water. This process occurs because their vapor pressure is lower than that of water vapor in the air. As they absorb moisture, they dissolve in the absorbed water, forming a saturated solution. Eventually, the solution becomes so concentrated that it flows as a liquid. This phenomenon is driven by exothermic hydration reactions, where energy is released, further promoting water absorption.