11.
The number of fundamental vibrational modes of CO2 molecule is

12.
The spectrum of radiation emitted by a black body at a temperature 1000 K peaks in the

13.
In a diatomic molecule, the inter-nuclear separation of the ground and first excited electronic state are the same as shown in the figure. If the molecule is initially in the lowest vibrational state of the ground state, then the absorption spectrum will appear as
Atomic and Molecular Physics mcq question image

15.
A three-level system of atoms has N1 atoms in level E1, N2 in level E2 and N3 in level E3 (N2 > N1 > N3 and E1 < E2 < E3). Lasere mission is possible between the levels

17.
An atom with one outer electron having orbital angular momentum $$l$$ is placed in a weak magnetic field. The number of energy levels into which the higher total angular momentum state splits, is