The shortest wavelength in hydrogen spectrum of Lyman series when RH = 109678 cm-1 is
1002.7 Å
1215.67 Å
1127.30 Å
911.7 Å
The electrons, identified by quantum numbers n and l,
(I) n = 3; l = 2; (II) n = 5; l = 0; (III) n = 4; l = 1; (IV) n = 4; l = 2; (V) n = 4; l = 0;
can be placed in order of increasing energy as-
I < V < III < IV < II
I < V < III < II < IV
V < I < III < II < IV
V < I < II < III < IV
The number of photons emitted per second by a 60 W source of monochromatic light of wavelength 663 nm is (h = 6 .63 × 10-34 Js)
4 × 10-20
1.5 × 1020
3 × 10-20
2 × 1020
Energy released, when one atom of uranium undergoes nuclear fission according to the following reaction is (atomic mass of U = 235.060; n = 1.009; Ba= 143.881 and Kr = 89.94 7) about
92U235 + 0n1 → 56Ba144 + 36Kr90 + 2 0n1
235 MeV
208 MeV
931.5 MeV
5.33 x 1023 MeV
Identify the nuclear reaction that differs from the rest.
γ- decay
κ- capture
Positron emission
β-decay
Which diagram best represents the appearance of the line spectrum of atomic hydrogen in the visible region?
The correct set of quantum numbers (n, l and m respectively) for the unpaired electron of chlorine atom is :
2, 1, 0
2, 1, 1
3, 1, 1
3, 2, 1
The relationship between the energy E1 of the radiation with a wavelength 8000 Å and the energy E2 of the radiation with a wavelength Å 16000 is:
E1 = 6E2
E1 = 2E2
E1 = 4E2
E1 = 4E2
B.
E1 = 2E2
Calculate the mass loss in the following.
[Given the masses : 2H = 2.014;3H = 3.016; He = 4.004; n = 1.008 amu]
0.018 amu
0.18 amu
0.0018 amu
1.8 amu
The observation that the ground state of nitrogen atom has 3 unpaired electrons in its electronic configuration and not otherwise is associated with:
Pauli's exclusion principle
Hund's rule of maximum multiplicity
Heisenberg's uncertainty relation
Ritz combination principle