In 1932, physicists engaged in studying the atom and its nucleus had only three particles to consider: the proton, the neutron ,and the electron.
举一反三
- What is the essence of cathode rays? A: proton B: neutron C: electron D: atom
- The number of can determine the chemical element. A: neutron B: electron C: atom D: proton
- Most of the atomic mass(质量) is concentrated in the nucleus, which explains why the nucleus is almost stationary within the atom, while the much lighter electron revolves round it.
- The nucleus(原子核) has a diameter(直径) only 0.01% of that of the atom itself.
- Which of the following is not a valid conclusion from Rutherford’s alpha particle scattering experiment? ( ) A: The nucleus must be positively charged B: The nucleus must be very small compared to the atom C: The atom is mainly empty space D: The mass of the atom is mostly concentrated in the nucleus