Mixing chocolate syrup with milk is a physical change. This is because when you combine the two substances, you are not altering their chemical structures; you’re simply blending them together. The chocolate syrup retains its properties, and the milk retains its properties as well. They can be separated again if desired, for example, by using a filter or allowing the mixture to settle with some time.
In a physical change, the composition of the substances remains the same, and they do not undergo a transformation into a new substance. Conversely, a chemical change involves a reaction that produces new substances with different properties. Combining chocolate syrup and milk is like mixing paint colors – the colors blend, but they don’t change into a different product.