8. In the 1960's how many fundamental forces were identified in physics? 9. Of the fundamental forces, which one is the weakest in strength? 10. Which of the fundamental forces has already been shown to be combined with the weak force? 11. All forces are believed to be transmitted via particles. Which particle transmits each of the following forces? Gravity? Electricity? Magnetism? , Strong force? Weak Force? 12. Which two fundamental forces only exist within the nucleus of atoms? and 13. Which force holds the nucleus together? 14. Which force is responsible for holding the neutron together and is responsible for beta decay