Which event represents a chemical change? breaking glass chopping wood crushing a can milk turning sour nextreset

  The event that represents a chemical change is milk turning sour.

  A chemical change occurs when a substance combines with another to form a new substance, this procces in general are not reversibles.

  In the case of the milk it contains a type of sugar called Lactose and also harmless bacterias called lactobacillus which uses the lactose to produce energy and creates lactic acid. This is the thing which makes milk taste sour.

  I hope that the answer help you.

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.