Question

Mark out the correct statement(s).
This question has multiple correct options.
A. Line spectra contain information about atoms only.
B. Line spectra contain information about both atoms and molecules.
C. Band spectra contain information about both atoms and molecules.
D. Band spectra contain information about molecules only.

Answer 1

Hint Line emission spectra can be obtained for atoms and molecules both. In line emission spectra, an atom or molecule which is in an excited state emits photons by making a transition from excited state to ground state.
The wavelength emitted by the molecular energy levels that are typically classified into many bunches are also classified and every group is well separated from the opposite. The spectrum during this case feels like a band spectrum.

Complete step-by-step solution :
Let us first discuss about line spectrum
A line spectrum is obtained once the emission happens from an associated atom, where the lines are usually unique and distinct in nature, whereas a band spectrum is within the kind of continuous bands that are obtained from molecules only.
In straightforward terms, a line spectrum consists of a spread of frequencies of electromagnetic radiations, usually emitted by elements, atoms or compound molecules at their lower energy states. Every spectrum in an exceedingly line emission is exclusive and distinct in nature.
So, the correct statement for line spectra is “Line spectra contain information about both atoms and molecules.”
Now, let’s discuss about the band spectrum
A band spectrum is mostly obtained from numerous line spectra. These are tightly stuck together in a continuous state. In contrast to line spectrum, the band spectra are obtained from numerous line spectra, although they differ in characteristics and properties. In physics, band emission is described as a part of the total emission from a blackbody, which comes in several intervals among certain wavelengths.

So, the correct statement for band spectrum is “Band spectra contain information about molecules only.” Hence, option B and option D are correct.

Note: As the spectral lines represent wavelengths radiated from atoms when electrons change from one energy level to another, so the line spectra are also called atomic spectra.
Band spectra is basically groups of lines that are so closely spaced that each group appears to be a band. Example: nitrogen spectrum.