Question: Use The Periodic Table of the Elements and the information below to answer the question. Magnesium metal (Mg) is grayish-white in color and reacts actively with water. Fluorine (F2) is a greenish-yellow gas at room temperature and is a member of the halogen family. These two elements react to produce magnesium fluoride (MgF2), a chemical commonly used in making windows and lenses. How does adding heat energy affect magnesium fluoride (MgF2) molecules?

  Options: 
 A. The motion of the molecules stops.
 B. The motion of the molecules increases.
 C. The motion of the molecules decreases.
 D. The motion of the molecules is at a constant rate.
Answer: B