Question

select the correct answer. a student places a sample of white sodium bicarbonate powder in a test tube and heats it. the student observes that the sodium bicarbonate undergoes a chemical change. after the change, what must be true about the substance in the test tube?
a. it is not white.
b. it is a liquid.
c. it is an element.
d. it is not sodium bicarbonate.

Explanation:

A chemical change means the original substance (sodium bicarbonate) is transformed into new substances. So after the change, the substance in the test tube can't be sodium bicarbonate anymore. Option A: Color change isn't guaranteed (e.g., some products might still be white). Option B: Heating sodium bicarbonate doesn't necessarily result in a liquid. Option C: Sodium bicarbonate is a compound, and its products are also compounds, not an element.

Answer:

D. It is not sodium bicarbonate.