Question

Which of the following can produced emission spectrum ?

• A. electrons in an excited gas jump up to a higher energy level and release photons.
• B. electrons in an excited gas jump down to a lower energy level and release photons.
• C. electrons are released from the outer orbitals of an excited gas.
• D. an unstable nucleus releases energy.
• E. light is shined on a metal surface and electrons are released.

Answer 1

Answer: (B)

electrons in an excited gas jump down to a lower energy level and release photons.

When an electron makes a transition from higher energy level to a lower one in an atom, a photon is released with energy equal to the difference in the energy of the levels. Such a spectrum of electromagnetic energy is called emission spectrum.