Question

classify each of the following changes as chemical or physical: rusting of iron, souring of milk, stretching a rubber band. use the references to access important values if needed for this question.

Explanation:

Rusting of iron is a chemical change as iron reacts with oxygen and moisture to form iron - oxide. Souring of milk is a chemical change due to the action of bacteria which convert lactose to lactic acid. Stretching a rubber band is a physical change as it only changes the shape of the rubber band without altering its chemical composition.

Answer:

Rusting of iron: Chemical
Souring of milk: Chemical
Stretching a rubber band: Physical