Physics Worksheet 1 Quantum Physics The Fundamental Forces a. e. Four Fundamental Forces: There are four fundamental forces in nature. Arrange them from the strongest to the weakest. f. (3) _________________________________ g. Among the four fundamental forces: Long-range forces: ____________________ ________________________ is responsible for the decay of some nuclear particles. e. In modern physics, particles are force carriers, because forces are brought about as a result of an (1) _________________________________ (2) _________________________________ (3) _________________________________ h. Classification of Matter a. Positrons – A particle whose ____________ is the same as electron’s, and whose ________________ is equal in magnitude but opposite in sign to the electron’s. ___________________________________. 2 Lepton – a particle that interacts through gravitational, weak, and electromagnetic forces, but not the ____________________ is called a lepton. A lepton is much lighter than a proton. Examples of leptons are Short-range forces: ____________________ d. Mesons – a meson is a particle of intermediate mass. A meson is made of ________________ and _______________. (4) _________________________________ ______________________________ holds the nucleon (protons and neutrons) together. Baryons – a baryons is an elementary particle that can be transformed into a A baryon is made of __________________. (2) _________________________________ c. Name: _________________ or ________________ and some number of mesons and lighter particles. (1) _________________________________ b. Section: Particles are classified according to the ___________________________________. they have with other particles. b. all four forces protons, neutrons If the force carrier particles (such as gluons, gravitons, etc.) are excluded, all particles can be classified into two groups – except strong force electrons, positions, neutrinos ________________ and _______________. c. Hadron – ___________________________________. d. The hadrons can be subdivided into no. of quark – no. of antiquark = 3 (B =1) ________________ and ________________ no. of quark = no. of antiquark (B = 0) according to their ____________________. The baryon number is defined as: ____________________________ where i. N is the number of ____________ N is the number of ____________ q Neutrino – a neutrino is a ______________ particle that has little mass but does possess both energy and momentum. q Both of them are composed of more € fundamental particles called ____________. € Mr. Lin 3 The Antiparticle 1