* Physical Change: A physical change alters the form or appearance of a substance but doesn't change its chemical composition. Examples include melting ice, cutting paper, or dissolving sugar in water.

* Chemical Change: A chemical change results in the formation of new substances with different properties. Examples include burning wood, rusting iron, or baking a cake.

* Mixture: A mixture is a combination of two or more substances where each substance retains its own properties. Mixtures can be separated by physical means (like filtration or evaporation).

Chocolate milk is a mixture because:

* The chocolate powder and milk are combined physically, not through a chemical reaction.

* You can separate the components of chocolate milk (chocolate and milk) by physical means. For example, you could let the milk sit and the chocolate would settle to the bottom.

Let me know if you have any other questions!