by nuclear connection by physically combining by magnetic connection by chemically combining
I gave my students this multiple choice 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 do the elements magnesium (Mg) and fluorine (F2) produce the compound magnesium fluoride (MgF2)?

Only one answer is correct among these 4 choices:
- by nuclear connection
- by physically combining
- by magnetic connection
- by chemically combining

Could you tell me which one is correct?

by chemically combining