A set of atoms in an excited state decays
1. | in general to any of the states with lower energy |
2. | into a lower state only when excited by an external electric field |
3. | all together simultaneously into a lower state |
4. | to emit photons only when they collide |
The Balmer series for the H-atom can be observed:
a. | if we measure the frequencies of light emitted when an excited atom falls to the ground state |
b. | if we measure the frequencies of light emitted due to transitions between excited states and the first excited state |
c. | in any transition in a H-atom |
d. | as a sequence of frequencies with the higher frequencies getting closely packed |
1. (b, c)
2. (a, c)
3. (b, d)
4. (c, d)