A-LEVEL A2 物理复习资料 particle physics

Section3 particle physics 1． The nuclear atom (1) Mass number and atomic number (2) Alpha particle scattering experiment (3) Electrons are accelerated by E and B (4) Write equations using standard nuclear notating (5)Explain why high energies are required to break particles into their constituents and to investigate fine structure (6) de Broglie wavelength λ=h/p (201306R-7)The de Broglie wavelength associated with electrons moving at 2.5 × 106 m s–1 is A .2.9 × 10–4m    B .2.4 × 10–8 m    C .2.9 × 10–10m    D .2.4 × 10–39m (201306-10) The de Broglie wavelength for neutrons used to study crystal structure is 1.2 nm. mass of a neutron = 1.67 × 10–27kg The speed of these neutrons would be A .3.0 × 106 m s–1  B.3.3 × 102m s–1  C.3.0 × 10–3m s–1  D.3.3 × 10–7m s–1 (201306R-8 )Which of the following is not a valid conclusion from Rutherford’s alpha particle scattering experiment?  A .The atom is mainly empty space. B .The mass of the atom is mostly concentrated in the nucleus. C. The nucleus must be positively charged. D .The nucleus must be very small compared to the atom. (201306R-9) Select the row in the table that correctly identifies the composition of a 23592U+ ion.   Number of protons Number of neutrons Number of electrons A 92 143 91 B 92 143 92 C 92 235 91 D 93 235 92         (201306-1)The nucleus of one of the isotopes of nickel is represented by 6028Ni. Which line correctly identifies a neutral atom of this isotope?   Number of protons Number of neutrons Number of electrons A 28 32 28 B 28 32 32 C 28 60 28 D 60 28 28         （201201-10） The de Broglie wavelength of a moving tennis ball is calculated as 1 × 10-33 m. This means that the moving tennis ball A .diffracts through a narrow slit.      B.does not behave as a particle. C.does not display wave properties.    D.is travelling at the speed of light. (201306R-10) .A transmission electron microscope passes a beam of electrons through a tiny specimen to form an image on a viewing screen Due to the wave nature of electrons, diffraction occurs which can blur the image. To reduce this effect when viewing a smaller object the beam must contain A .more electrons per second.        B .fewer electrons per second. C. faster moving electrons.          D .slower moving electrons (201306-13).In an experiment to investigate the    structure    of the atom, α-particles are fired at a thin metal foil,    which causes the    α-particles to scatter. (a)    (i) State    the    direction in which the    number    of α-particles detected will be    a    maximum (ii) State what this suggests about the structure of the atoms in the metal foil. (b) Some α-particles    are    scattered through    180°. State what this suggests about the structure of the atoms in the metal foil. (c)    The    diagram    shows the path of an    α-particle passing near to    a single    nucleus    in    the    metal foil. (i)Name the force that causes the    deflection of    the α-particle. (ii) On the diagram, draw an arrow to show the direction of the force acting on the α-particle at the    point where    the    force is    a maximum. Label the force F. (iii) The foil is replaced by a metal of greater proton number. Draw the path of    an α-particle    that    has    the    same initial    starting    point and velocity as the one drawn in the diagram. (201301-11) Early in the twentieth century physicists observed the scattering of alpha particles after they had passed through a thin gold foil.  This scattering experiment provided evidence for the structure of the atom. (a) State why it is necessary to remove the air from the apparatus that is used for this experiment. (b) From the results of such an experiment give two conclusions that can be deduced about the nucleus of an atom. Conclusion 1 Conclusion 2 (c) The diagram shows three α-particles ,all with the same kinetic energy .The path followed by one of the particles is shown . Add to the diagram to show the paths followed by the other two particles. (201302-12 )The electron in a hydrogen atom can be described by a stationary wave which is confined within the atom.This means that the de Broglie wavelength associated with it must be similar to the size of the atom which is of the order of 10–10 m. (a)(i)Calculate the speed of an electron whose de Broglie wavelength is1.00 × 10–10m. (ii) Calculate the kinetic energy of this electron in electronvolts