Q1: A colloidal system, in which a liquid is dispersed in gas is called a/an

ANS:B - aerosol

An aerosol is a colloidal system consisting of tiny particles of solid, liquid, or both dispersed in a gas. These particles can range in size from nanometers to micrometers. Aerosols are ubiquitous in nature and can be found in various forms, including fog, smoke, mist, and haze. They are also widely used in many industrial, medical, and household applications. Aerosols play crucial roles in atmospheric processes, such as cloud formation, and can impact climate by scattering or absorbing sunlight, as well as by serving as nuclei for condensation or freezing in the atmosphere. In addition to natural sources like volcanic eruptions and forest fires, aerosols are also generated by human activities such as combustion processes, industrial emissions, and transportation. In everyday life, aerosols are commonly encountered in products like spray paints, insecticides, air fresheners, and personal care products such as hairspray and deodorants. These products typically use propellants to disperse liquid contents into fine droplets, creating a mist or spray that can be easily applied. Aerosol science encompasses the study of the formation, behavior, and properties of aerosols, as well as their environmental and health impacts. Understanding aerosols is essential for various fields, including atmospheric science, environmental engineering, materials science, and pharmacology.