The diagram represents some electron transitions between energy levels in an atom - Scottish Highers Physics - Question 16 - 2015

To find the transition that emits the radiation with the shortest wavelength, we need to find the energy difference associated with each transition, as a higher energy difference results in shorter wavelengths of emitted radiation.

The energy transitions are as follows:

1. Transition from E1 to E0:

   $ext{Energy} = E0 - E1 = (-21.8 × 10^{-19} J) - (-1.4 × 10^{-19} J) = -20.4 × 10^{-19} J$

2. Transition from E2 to E0:

   $ext{Energy} = E0 - E2 = (-21.8 × 10^{-19} J) - (-2.4 × 10^{-19} J) = -19.4 × 10^{-19} J$

3. Transition from E3 to E0:

   $ext{Energy} = E0 - E3 = (-21.8 × 10^{-19} J) - (-5.4 × 10^{-19} J) = -16.4 × 10^{-19} J$

The biggest energy difference is from E1 to E0, thus corresponding to the shortest wavelength radiation.

Therefore, the correct answer is E1 to E0 (Option E).