What is the half-life of a radioisotope? a. the amount of time it takes for half of the material to decay b. the amount of time a radioisotope exists as the parent element c. the amount of time it takes for a radioisotope to get halfway to a stable form d. the amount of time it takes for half of the radioisotope to form

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