Work in pairs or groups. Read the following definitions and decide what they mean

1. either of the subatomic particles, the proton and the neutron, constituting atomic nuclei. Protons (positively charged) and neutrons (uncharged) behave identically under the influence of the short-range nuclear force, both in the way they are bound in nuclei and in the way they are scattered by each other

2. type of fundamental particle with no electric charge, little or no mass, and one-half unit of spin. Belong to the family of particles called leptons, which are not subject to the strong nuclear force. There are three types, each associated with a charged lepton—i.e., the electron, muon, and tau

3. any member of a group of subatomic particles having odd half-integral angular momentum (spin 1/2, 3/2); named for the Fermi-Dirac statistics that describe its behaviour. Include particles in the class of leptons (e.g., electrons, muons), baryons (e.g., neutrons, protons, lambda particles), and nuclei of odd mass number (e.g., tritium, helium-3, uranium-233)

4. a stable subatomic particle that has a unit-positive charge and a mass of 1.6726231 × 10−27 kg, which is 1,836 times the mass of an electron

5. also called elementary particle any of various self-contained units of matter or energy. More than 200 have been detected, and each appears to have an antiparticle, an antimatter counterpart with the identical mass but opposite electric charge, magnetic moment, or spin

6. lightest stable subatomic particle known. It carries a negative charge which is considered the basic charge of electricity

7. one of the constituent particles of every atomic nucleus except ordinary hydrogen; it has no electrical charge and its mass is nearly 1,840 times that of the electron

8. any member of a class of fermions that respond only to electromagnetic, weak, and gravitational forces and do not take part in strong interactions

9. subatomic particle with integral spin (i.e., angular momentum in quantum-mechanical units of 0, 1, etc.) that is governed by the Bose-Einstein statistics (q.v.). Include mesons (e.g., pions and kaons), nuclei of even mass number (e.g., helium-4), and the particles required to embody the fields of quantum field theory (e.g., photons and gluons)

10. any of a group of subatomic particles believed to be among the fundamental constituents of matter. Constitute all hadrons (baryons and mesons)—i.e., all particles that interact by means of the strong force; the force that binds the components of the nucleus

Date: 2015-05-18; view: 556; Нарушение авторских прав