Which source is associated with a line emission spectrum ?
Electric fire
Neon street sign
Red traffic light
Sun
In a Rutherford scattering experiment when a projectile of charge Z1 and 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 x M2
directly proportional to Z1 Z2
inversely proportional to Z1
directly proportional to mass M1.
The total energy of an electron in the first excited state of hydrogen is about – 3.4 eV. Its kinetic energy in this state is
-3.4 eV
- 6.8 e V
6.8 eV
3.4 eV
The valence electron in alkali metal is a
f – electron
p – electron
s – electron
d – electron
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
The ionization energy of the electron in the hydrogen atom in its ground state is 12.6 eV. The atoms are excited to higher energy levels to emit radiations of 6 wavelengths. Maximum 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
When electron jumps from n = 4 to n = 2 orbit, we get :
second line of Lyman series
second line of Balmer series
second line of Paschen series
an absorption line of Balmer series
Bohr's model is based on :
Conservation of linear momentum
Conservation of angular momentum
Conservation of quantum frequency
Conservation of energy
In terms of Bohr radius α0, the radius of the second Bohr orbit of a hydrogen atom is :
4 α0
8 α0
√ 2 α0
2 α0
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
