The correct answer is 'X' is a true solution; 'Y' is a colloid. Concept: Mixtures: A mixture is a substance that consists of two or more elements or compounds not chemically combined together. For Example - Air is a mixture of gases like oxygen, nitrogen, argon, CO2, and water vapor. Types of Mixtures: Homogeneous Mixture: Those mixtures, in which the substances are completely mixed together and are indistinguishable from one another, are called homogeneous mixtures. For example Soda water, Soft drinks, lemonade, salt or sugar solution, etc. Heterogeneous Mixture: Those mixtures in which the substances remain separate and one substance is spread throughout the other substance as small particles, droplets, or bubbles are called heterogeneous mixtures. All the suspensions and colloids are heterogeneous mixtures. For Example: - Sugar and sand mixture, muddy river water, soap solution. Explanation: Mixtures can be classified into solutions, colloids, and suspensions on the basis of the size of the particles they are made of. True Solution Colloid Suspension It is a form of homogeneous mixture It appears to be homogeneous but actually, it is heterogeneous It is a form of a heterogeneous mixture Particle size is less than 1 nm Particle size range from 1 and 1000 nm Particle size greater than 1000 nm Particles do not settle when left undisturbed Particles do not settle down Particles settle down well Cannot be separated by filtration Cannot be separated by filtration Can be separated by filtration It does not scatter light It Shows the Tyndall effect (scatters light) May scatter light Particles are not visible to the naked eye Particles are not visible through the naked eye Particles are easily visible through the naked eye X is homogeneous and doesn't scatter light. So, it is a true solution. Y appears to be homogenous but scatters light. So, it is a colloid.