In terms of Bohr radius a0, the radius of the second Bohr orbit of hydrogen atom is given by
4 a0
8 a0
√2 a0
2 a0
An α-particle of energy 5 MeV is scattered through 180o by a fixed uranium nucleus. The distance of the closest approach is of the order of
1 Å
10-10 cm
10-12 cm
10-15 cm
Which source is associated with a line emission spectrum?
Electric fire
Neon street sign
Red traffic light
Sun
The ionization energy of the electron in the hydrogen atom in its ground state is 13.6 eV. The atoms are excited to higher energy levels to wavelength of emitted radiation corresponds to the transition between
n = 3 to n = 2 states
n = 3 to n = 1 states
n = 2 to n = 1 states
n = 4 to n = 3 states
In the Bohr model of the hydrogen atom, let R, V and E represent the radius of the orbit, the speed of electron and the total energy of the electron respectively.Which of the following quantity is proportional to the quantum number n?
E/V
R/E
VR
RE
The Bohr model of atoms
assumes that the angular momentum of electrons is quantized
uses Einstein’s photoelectric equation
predict continuous emission spectra for atoms
predicts the same emission spectra for all types of atoms
Hydrogen atoms are excited from ground state of the principal quantum number 4. Then the number of spectral lines observed will be
3
6
5
2
If the electron in a hydrogen atom jumps from an orbit with level n2 = 3 to an orbit with level n1 = 2, the emitted radiation has a wavelength given by
λ = 6/R
λ = R/6
