Question

Which mathematical relation represents the energy of a photon emitted during an electronic transition from state ni to state nf?

Options

• \[h\nu_{if} = \frac{E_{ni}}{E_{nf}}\]

• \[h\nu_{if} = E_{nf} - E_{ni}\]

• \[h\nu_{if} = E_{ni} + E_{nf}\]

• \[h\nu_{if} = E_{ni} - E_{nf}\]

Answer 1

The energy difference between the initial state (ni) and final state (nf) equals the photon energy. Since nf < ni (lower to higher transition), the difference Eni − Enf is positive, yielding the photon frequency νif through the relation \[h\nu_{if} = E_{ni} - E_{nf}\].