Scientists put a few drops of dilute hydrochloric acid on a lab table. For safety purposes, the scientist because some baking soda on to the spill. Which observation would provide the best evidence that chemical reaction occurred?

F. The baking soda in hydrochloric acid combined, and bubbles formed.

G. The baking soda absorb the hydrochloric acid.

H. Some of the baking soda dissolved in the acid

J. The hydrochloric acid evaporated, Leaving only the baking soda

F. The baking soda combined with the hydrochloric acid and bubbles formed.

Explanation:

The formation of gas bubbles is usually a sign of a chemical reaction.

G. is wrong because the absorption of a liquid by a solid is a physical process. Think of using a paper towel to clean up spilled water.

H. is wrong because the dissolving of a solid is a physical process. Think of dissolving sugar in your coffee.

J. is wrong because evaporation is a physical process. Think of a puddle of water drying up in the hot sun.