CBSE
J.J. Thomson's cathode ray tube experiment demonstrated that
cathode rays are streams of negatively charged ions
all the mass of an atom is essentially in the nucleus
the e/m of electrons is much greater than the e/m of protons
the e/m ratio of the cathode ray particles changes when a different gas is placed in the discharge tube
Wavelength of light emitted from second orbit to first orbit in a hydrogen atom is
6563
4102
4861
1215
Band spectrum is also called
molecular spectrum
atomic spectrum
flash spectrum
line absorption spectrum
The ionization potential of hydrogen is 13.6 V. The energy required to remove an electron from the second orbit of hydrogen is
3.4 eV
6.8 eV
13.6 eV
1.51 eV
The ratio of the de-Broglie wavelength of an -particle and a proton of same kinetic energy is
1 : 2
1 : 1
1 :
4 : 1
The ionisation potential of hydrogen atom is -13.6 eV. An electron in the ground state of a hydrogen atoms absorbs a photon of energy 12.75 eV. How many different spectral line can one expect when the electron make a downward transition ?
1
4
2
6
If the electron in a hydrogen atom jumps from an orbit with level n1 = 2 to an orbit with level n2 = 1 the emitted radiation has a wavelength given by
The de-Broglie wavelength of an electron moving with a velocity c/2 (c = velocity of light in vacuum) is equal to the wavelength of a photon. The ratio of the kinetic energies of electron and photon is
1 : 4
1 : 2
1 : 1
2 : 1
Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is
The ionization energy of hydrogen is 13.6 eV. The energy of the photon released when an electron jumps from the first excited state (n = 2) to the ground state of a hydrogen atom is
3.4 eV
4.53 eV
10.2 eV
13.6 eV