Physics - Modern Physics Question with Solution | TestHub

Absorption means an upward jump: $1\to 2(10.2\mathrm{eV}),2\to 3(1.89\mathrm{eV}),2\to 5(2.86\mathrm{eV});4\to 3$ is downward (emission). The smallest energy gap, $2\to 3$, absorbs the longest wavelength.