The total energy of electron in the ground state of hydrogen atom is -13.6 eV. The kinetic energy of an electron in the first excited state is
3.4 eV
6.8 eV
13.6 eV
1.7 eV
In a Rutherford scattering experiment when a projectile of charge Z1and mass M1 approaches a target nucleus of charge Z2 and Mass M2, the distance of closest approach is r0. The energy of the projectile is
directly proportional to M1 × M2
directly proportional to Z1 Z2
inversely proportional to Z1
directly proportional to Mass M1
Which source is associated with a line emission spectrum?
Electric fire
Neon street sign
Red traffic light
Sun
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
When a hydrogen atom is raised from the ground state to an excited state
potential energy decreases and kinetic energy increases
potential energy increases and kinetic energy decreases
Both kinetic energy and potential energy decrease
Absorption spectrum
Hydrogen atom emits blue light when it changes from n = 4 energy level to n = 2 level. Which colour of light would the atom emit when it changes from n = 5 level to n = 2 level?
red
yellow
violet
green
The ionization energy of hydrogen atom is 13.6 eV. Following Bohr’s theory, the energy corresponding to a transition between 3rd and 4th orbit is
3.40 eV
1.51 eV
0.85 eV
0.66 eV
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
In the Bohr’s model of a hydrogen atom, the centripetal force is furnished by the Coulomb attraction between the proton and the electron. If a0 is the radius of the ground state orbit, m is the mass and e is the charge on the electron, ε0 is the vacuum permittivity, the speed of the electron is
zero