PLEASE HURRY Which of the following correctly describes an independent variable The variable you are testing in an experiment

The variable you can change in an experiment

The variable that the experimenter has control over

All of the above

Calculate the number of molecules present in 0.750 mol of mgo.

6what is the importance of water on earth? a) it keeps the top layer of the geosphere cool b) it allows life to exist c) it provides ice at the poles d) it creates earth's blue color from space

Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.