A. an atom has limited number of ionization potentials but a large number of excitation potentials B. there are as many excitation potentials as there are excited states C. the difference between the energy of the ground sate and any one of the excited states is the measure of excitation energy D. all of above...
A. radiate electromagnetic energy with a continuous distribution of wavelength B. absorb particular wavelengths when white light is incident on them C. radiate electromagnetic energy of discrete characteristic wavelength D. emit either invisible or visible light...
A. The ions in a crystal are well arranged B. The lines in a diffraction grating cannot reflect X-rays. C. The penetration power of X-rays is high in a diffraction grating D. The wavelengths of X-rays are of the same order of magnitude as the separation between atoms in a crystal...
A. It does emit radiation B. Its size as compare to proton and neutron is very small C. No antiparticle of electron is present D. The velocity of electron must be very high according to uncertainty principle...
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