They form over warm and tropical bodies of water. Warm air will rise over the water and will start becoming cool air. If the process keeps going, clouds will eventually form and cause a hurricane.
Thunderstorms, warm ocean water and light wind are needed for a hurricane to form (A). Once formed, a hurricane consists of huge rotating rain bands with a center of clear skies called the eye which is surrounded by the fast winds of the eyewall (B).
You would expect a scratch on the quartz since quartz is on a hardness scale of 7 and the mineral you are rubbing against it is at a hardness scale of 7.5
The factor that is different between the control and experimental is known as the independent variable. This variable is independent because it does not depend on what happens in the experiment.
