Final answer:
The term 'Heterogeneous' does not fit with the other terms as it represents mixtures with non-uniform distribution, while the others refer to homogeneous mixtures (solutions and colloids) or examples thereof, like smoke.
The correct option is a.
Step-by-step explanation:
The term that does not fit the group consisting of Smoke, Homogeneous, Heterogeneous, Solution, Colloid, and Suspension is d) Heterogeneous.
A homogeneous mixture is a mixture in which the composition is uniform throughout the mixture. All solutions (including gases, liquids, and solids) and colloids fall under the category of homogeneous mixtures due to their uniform distribution of particles.
Examples include salt water (a solution where salt is dissolved uniformly in water) and milk (a colloid where fat particles are uniformly dispersed in the liquid).
On the other hand, a heterogeneous mixture is one in which the different components are not uniformly distributed, and the composition can vary from one region to another.
Suspensions like mud in water are examples of heterogeneous mixtures, as they contain particles that eventually settle out and are not uniformly distributed.
Smoke can be confusing as it can be seen as a collection of solid particles dispersed in a gas, but it is colloidal in nature, which is a type of homogeneous mixture—making the term 'Heterogeneous' the odd one out in this context.
The correct option is a.