In this case, we need to change the hours of studying to see how studying for different hours [1 hr, 2hr, etc (( Independant variable coz we're changing the no. of hours)) ] is going to affect the student's score, and in the end, we are measuring the score of each student [this is the dependant variable].
If hydrogen gas is passed over heated copper oxide (CuO), the black coating on the surface turns brown as the reverse reaction takes place and copper is obtained
