Which statement about pure substances and molecules is correct? O All pure substances are molecules.
O All molecules are pure substances.
o Molecules cannot be pure substances.
O Pure substances cannot be molecules.

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