Question

which of these is an example of a chemical change? all of these burning a piece of toast a pear turning brown yogurt turning sour

Explanation:

A chemical change results in new substances with different properties. Burning toast creates carbon - based substances and other compounds. A pear turning brown is due to oxidation reactions forming new compounds. Yogurt turning sour is because of fermentation reactions producing lactic acid and other substances. All are chemical changes.

Answer:

A. All of these