Two currents in opposite directions which way is magnetic field

How many moles of oxygen gas are produced from the decomposition of six moles of potassium chlorate

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

Is this correct if not can u correct me