In a science demonstration, a teacher mixed zinc (zn) with hydrogen chloride (hcl) in a flask and quickly attached a balloon over the mouth of the flask. bubbles formed in the solution and the balloon inflated.

The famous scientist galileo galilei did several experiments with sloping planes, which he rolled metal balls down so that he could study motion. by changing the slope, he could study how the speed at which the ball rolled was affected. what was the independent variable in galileo's experiment? a. the speed of the ball b. the slope of the plane c. whether the ball moved d. what the ball was made of