Respuesta :
The yeast and Hydrogen Peroxide is the chemical change, because when something is changed chemically, there is a chemical added that cannot be taken away to make it go back to it's original state. However when you're blowing bubbles in milk, no chemicals were added and it will go back to it's original state.
Answer:
If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.
Explanation: