Here's why:

* Heterogeneous mixtures have components that are not evenly distributed throughout. This means that if you take samples from different parts of the mixture, they will likely have different proportions of each component.

* Homogeneous mixtures, on the other hand, have components that are evenly distributed. This means that samples from any part of the mixture will have the same proportions of each component.

Examples of heterogeneous mixtures:

* Sand and water: The sand settles to the bottom, making it unevenly distributed.

* Oil and water: Oil floats on top of water, creating distinct layers.

* Trail mix: Different ingredients like nuts, raisins, and chocolate chips are not uniformly spread.

Let me know if you have any other questions!