Spectra

Question 1

What is an emission line spectra?

Answer 1

Each element produces a unique emission line spectrum because of its unique set of energy levels

Question 2

What is a continuous spectra?

Answer 2

All visible frequencies or wavelengths are present. The atoms of a heated solid metal will produce this type of spectrum.

Question 3

What is an absorption line spectra?

Answer 3

This type of spectrum has series of dark spectral lines against the background of a continuous spectrum. The dark lines have exactly the same wavelengths as the bright emission spectral lines for the same gas atoms

Question 4

When is an absorption line spectra formed?

Answer 4

When light from a source that produces a continuous spectrum passes through a cooler gas.

Question 5

Why do you get an absorption spectra?

Answer 5

• At low temperatures, most of the electrons in the gas atoms will be in their ground states.
• Photons of the correct wavelength are absorbed by the electrons to excite them to higher energy levels.
• These wavelengths are missing from the continuous spectrum when it comes out on the other side.
• You see a continuous spectrum with black lines in it corresponding to the absorbed wavelengths.