The following set of four questions has to do with the four physical forces of nature. A letter answer on the right can only be used once. Indicate your match beside the question on the left. Quarks to DNA and Four Forces Question 27 options: Weak force of the atom Gravity Strong force of the atom Electro-magnetism 1. always attractive, never repulsive 2. can change an element's atomic number, transforming it into the nucleus of a different chemical element. 3. underlying source of nuclear reactions that power the stars 4. governs the emission and absorption of light and other forms of electromagnetic radiation