Question

which of the following electron transitions (energy transition) in the model of the oxygen atom above would be accompanied by the emission of a photon?
a complete orbit within level 1
moving from level 1 to level 2
moving from level 2 to level 1
moving from level 0 to level 3

Explanation:

Electrons emit photons when moving from a higher - energy level to a lower - energy level. Among the options, moving from Level 2 to Level 1 is a transition from a higher to a lower energy level. Transitions from lower to higher levels require absorption of energy, and moving within the same level does not involve photon emission.

Answer:

Moving from Level 2 to Level 1