21232.The ionization enthalpy of hydrogen atom is 1.312 × 106 J mol-1. The energy required to excite the electron in the atom from n = 1 to n = 2 is
8.51 × 105 Jmol-1
6.56 × 105 Jmol-1
7.56 × 105 Jmol-1
9.84 × 105 Jmol-1
21233.When the azimuthal quantum number has the value of 2, the number of orbitals possible are
7
5
3
0
21234.What is the correct order of spin only magnetic moment (in BM) of Mn+2 and V+2 ?
Mn2+ > V 2+ > Cr2+
V 2+ > Cr2+ > Mn2+
Mn2+ > Cr2+ > V 2+
Cr2+ > V 2+ > Mn2+
21235.Two electrons occupying the same orbital are distinguished by
Azimuthal quantum number
Spin quantum number
Principal quantum number
Magnetic quantum number
21236.The electronic configuration of an element is 1s2 2s2 2p6 3s2 3p6 3d5 4s1. This presentation is
excited state
ground state
cationic form
anionic form
21237.Uncertainty in the position of an electron (mass = 9.1 × 10–31 kg) moving with a velocity 300 ms–1, accurate upto 0.001%, will be
(h = 6.63 × 10–34 Js)
(h = 6.63 × 10–34 Js)
19.2 × 10–2 m
5.76 × 10–2 m
1.92 × 10–2 m
3.84 × 10–2 m
21238.In a multi–electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic acid and electric fields?
(a) n = 1, l = 0, m = 0
(b) n = 2, l = 0, m = 0
(c) n = 2, l = 1, m = 1
(d) n = 3, l = 2, m = 1
(e) n = 3, l = 2, m = 0
(a) n = 1, l = 0, m = 0
(b) n = 2, l = 0, m = 0
(c) n = 2, l = 1, m = 1
(d) n = 3, l = 2, m = 1
(e) n = 3, l = 2, m = 0
(a) and (b)
(b) and (c)
(c) and (d)
(d) and (e)
21239.The energy of an electron in first Bohr orbit of H-atom is –13.6 eV. The possible energy value of electron in the excited state of Li2+ is
– 122.4 eV
30.6 eV
– 30.6 eV
13.6 eV
21240.Which of the following statements in relation to the hydrogen atom is correct?
3s orbital is lower in energy than 3p orbital
3p orbital is lower in energy than 3d orbital
3s and 3p orbitals are of lower energy than 3d orbital
3s, 3p and 3d orbitals all have the same energy
21241.α-particles, β-particles and γ-rays are all having same energy. Their penetrating power in a given medium in increasing order will be
β, γ, α
γ, α, β
α, β, γ
β, α, γ
21243.Which of the following is not permissible?
n = 4, l = 3, m = 0
n = 4, l = 2, m = 1
n = 4, l = 4, m = 1
n = 4, l = 0, m = 0
21244.An electron in hydrogen atom makes a transition n1 → n2 where n1 and n2 are principal quantum numbers of the two states. Assuming Bohr's model to be valid, the time period of the electron in the initial state is eight times that in the final state. The possible values of n1 and n2 are
n1 = 4 and n2 = 2
n1 = 6 and n2 = 2
n1 = 8 and n2 = 1
n1 = 8 and n2 = 2
21245.The electronic transitions from n = 2 to n = 1 will produce shortest wavelength in (where n = principal quantum state)
Li+2
He+
H
H+
21246.Which of the following pair of ions have same paramagnetic moment?
Cu+2, Ti+3
Mn+2, Cu+2
Ti+4, Cu+2
Ti+3, Ni+2
21247.Which of the following sets of quantum numbers represents the highest energy of an atom?
n = 3, l = 2,m = 1, s = +1/2
n = 3, l = 2,m = 1, s = +1/2
n = 4, l = 0,m = 0, s = +1/2
n = 3, l = 0,m = 0, s = +1/2
21248.Which one of the following expressions represent the electron probability function
4πr drψ2
4πr2 drψ
4πr2 drψ2
4πr drψ
21249.Which one of the following has unit positive charge and 1 amu mass?
Electron
Neutron
Proton
None of these
21250.Which one of the following statement is not correct?
Rydberg's constant and wave number have same units
Lyman series of hydrogen spectrum occur in the ultraviolet region
The angular momentum of the electron in the ground state hydrogen atom is equal to h/2π
The radius offirst Bohr orbit of hydrogen atom is 2.116 × 10–8 cm.
21251.Which transition in the hydrogen atomic spectrum will have the same wavelength as the transition, n = 4 to n = 2 of He+ spectrum?
n = 4 to n = 3
n = 3 to n = 2
n = 4 to n = 2
n = 2 to n = 1