* Physical Changes: Alter the form or appearance of a substance but don't change its chemical composition.

* Chemical Changes: Result in the formation of new substances with different chemical properties.

When you dye a carnation, you're essentially adding a colored dye to the water it's absorbing. The dye travels up the stem and into the petals, giving the carnation a new color. The carnation itself hasn't undergone a chemical reaction; it's simply been stained.

Key points:

* The carnation's chemical makeup (its flower cells, etc.) remains the same.

* You can reverse the color change by removing the carnation from the dyed water and letting it absorb plain water.

Therefore, changing the color of a carnation is a physical change.