Question

Which statement is correct about line emmission spectrum?

I. The lines converge at lower energies
II. Electron transition to n=1 are responsible for lines in the UV region
III. Lines are produced when electrons move from higher to lower energy levels

A.I and II only
B. I and III only
C. II and III only
D. I,II and III

Answer 1

for I Because lower electron energy transitions n=1 :rarrow: n=2 or 2 to 3 or 3 to 4 etc are smaller in energy than say, 5 :rarrow: 6 or 7 :rarrow: 8
and lower energy transitions correspond to lower energy photons which equals shorter wavelengths. So the first few transitions might be very close in energy, meaning their emitted photons will "converge" while the higher energy transitions will have a MUCH larger energy difference and therefore more spread out in the spectrum

Answer 2

The hydrogen emission spectrum consists of several series of lines, named for their discoverers. A series of emission lines consists of those electronic transitions which all terminate at the same final level. For example, transitions in the Lyman series, which appear in the UV region of the spectrum, all terminate at the ground electronic state of the hydrogen atom. The Paschen, Brackett, and Pfund series of lines are found in the infrared region.
2nd one is also correct
3rd is also correct because When an atom is heated the electrons jump to higher energy levels. Eventually they drop back down one or two or three levels emitting light energy. Each jump has a distinct package of energy and hence wavelength and thus produces a single line of the spectrum. A sodium street light is orange because it has 2 very strong orange lines as well as some fainter ones.

Answer 3

Thank you for the answers so you're telling me that D is the right answer then? @sarah786

Answer 4

yes .. i think so after reading all the facts and figures and ur welcom..:)