Which of the following could happen when infrared radiation is absorbed by a molecule ?
a) molecules begins to rotate more rapidly
b) molecule may glow in the dark
c) electrons are promoted from filled to empty molecular orbitals
d) the orientation of a nuclear spin state changes.
e) intramolecular bond angles change

       E) Intramolecular bond angles change

Explanation:

Infrared Radiation:

IR is electromagnetic radiations. The wavelength i.e. 700nm to 1000 mm of infrared is longer than invisible light and Its frequency is lower than light, that's why it is invisible to light.

So

The correct option is option E

       E) Intramolecular bond angles change

* Note:

it couldn't be option A as the frequency of IR is not enough to rotate a whole molecule

It Couldn't be option B as IR rations are electromagnetic radiation of longer wave length so it one can not see it with light so how it will glow a molecule

It also not could be the option C as for the excitation of electrons require much higher energy.

It also not the option D as nuclear magnetic spin is associated with nuclear magnetic radiation that are much different from IR.

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.