The de-Broglie wavelength of a particle with mass 1g and velocity 100 m/s is
6.63×10-33 m
6.63×10-34 m
6.63×10-35 m
6.63×10-36 m
For which one of the following sets of four quantum numbers, an electron will have the highest energy ?
n l m s
3 2 1
4 2 -1
4 1 0 -
5 0 0 -
The position of both, an electron and a helium atom is known within 1.0 mm. Further the momentum of the electron is known within 5.0×10-26 kg ms-1 . The minimum uncertainty in the measurement of the momentum of the helium atom is
50 kg ms-1
80 kg ms-1
80×10-26 kg ms-1
5.0×10-26 kg ms-1
In hydrogen atom, energy of first excited state is -3.4 eV. Then, KE of same orbit of hydrogen atom is
+ 3.4 eV
+ 6.8 eV
- 13.6 eV
+ 13.6 eV
In a given atom no two electrons can have the same values of all the four quantum numbers. This is called
Hund's rule
Aufbau principle
Uncertainty principle
Pauli's exclusion principle
The orientation of an atomic orbital is governed by
azimuthal quantum number
spin quantum number
magnetic quantum number
principal quantum number
If ionisation potential for hydrogen atom is 13.6eV, then ionisation potential for He+ will be
54.4 eV
6.8 eV
13.6 eV
24.5 eV
The maximum number of electrons in a subshell is given by the expression
4l-2
4l + 2
2l + 2
2n2
Which of the following statements do not form a part of Bohr's model of hydrogen atom ?
Energy of the electrons in the orbits are quantised
The electron in the orbit nearest the nucleus has the lowest energy
Electrons revolve in different orbits around the nucleus
The position and velocity of electrons in the orbit cannot be determined simultaneously
Which of the following is not permissible arrangement of electrons in an atom ?
n = 4, l = 0, m = 0, s = -1/2
n = 5, l = 3, m = 0, s = + 1/2
n = 3, l = 2, m = -3, s = -1/2
n = 3, l = 2, m = -2, s = -1/2
