What is a heterogeneous mixture?

A heterogeneous mixture is characterized by the uneven distribution of its components. In such mixtures, the different substances remain distinct and can often be seen as separate phases or layers. This means that, when you look at a heterogeneous mixture, you can identify the various parts that make it up, and they do not blend seamlessly into one uniform substance.

For example, a salad or a bowl of cereal with milk are common occurrences of heterogeneous mixtures; the individual components – lettuce, tomatoes, cucumbers, or cereal pieces – retain their individual properties and can be easily distinguished. Each part maintains its own characteristics and does not become uniformly distributed throughout the mixture.

In contrast, a mixture with pure substances evenly distributed throughout would describe a homogeneous mixture, where the individual components blend to form a single phase, and cannot be easily separated by physical means, such as saltwater or air. Thus, the key aspect that defines a heterogeneous mixture is this characteristic of uneven distribution, making option B the accurate choice.