Answer:
Fe(NO2)3
Explanation:
A poly atomic ion is an ion that contains more than one atom.
If we look at all the compounds that have been mentioned among the options; KBr and NaF are both ionic but do not contain any covalent poly atomic ion.
However, Fe(NO2)3 contains NO2^+ which is a poly atomic ion that contains the covalent bond.
<span>When the electron in a hydrogen atom transitions from a high energy state to a lower energy state, the energy lost from the electron is used to produce a photon corresponding to the loss of energy. That photon will correspond to exactly 1 wavelength. And since a hydrogen atom has only 1 electron, at any given moment, it can only produce 1 photon. And in order to simultaneously produce 4 photons for 4 spectral lines, that would require a simultaneous transition of 4 electrons which is 3 too many for a hydrogen atom.</span>
The correct answer:C) NaCl(s)
Hope this helps!