Number of unpaired electrons in N2+ is/are
2
0
1
3
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
Uncertainty in position of an electron (mass = 9.1×10-28 g) moving with a velocity of 3×104 cm/s accurate upto 0.001% will be (use in certainty expression where h = 6.626×10-27 erg-s)
1.93 cm
3.84 cm
5.76 cm
7.68 cm
The maximum number of electrons in a subshell is given by the expression
4l-2
4l + 2
2l + 2
2n2
Consider the following sets of quantum numbers
n l m s
(i) 3 0 0 +1/2
(ii) 2 2 1 +1/2
(iii) 4 3 -2 -1/2
(iv) 1 0 -1 -1/2
(v) 3 2 3 +1/2
Which of the following sets of quantum number is not possible ?
(ii), (iii) and (iv)
(i), (ii), (iii) and (iv)
(ii), (iv) and (v)
(i) and (iii)
If an electron has spin quantum number + and magnetic quantum number -1, it cannot be present in
d-orbital
f-orbital
p-orbital
s-orbital
The total number of electrons that can be accommodated in all the orbitals having principal quantum number 2 and azimuthal quantum number 1 are
4
6
8
When an electron of charge e and mass m moves with a velocity v about the nuclear charge Ze in circular orbit of radius r, the potential energy of the electrons is given by
The measurement of the electron position is associated with an uncertainty in momentum, which is equal to 1×10-18 g cm s-1 . The uncertainty in electron velocity is, (mass of an electron is 9×10-28 g)
1×109 cm s-1
1×106 cm s-1
1×105 cm s-1
1×1011 cm s-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
