Video Transcript
The diagram below shows the energy
levels and their values for an atom containing a single electron. How much energy does an electron
need to move from the K level to the L level?
Energy levels are regions around
the nucleus in which electrons move according to their energies. The energy levels in the given
diagram are K, L, M, and N. The energy of a level depends on
its distance from the nucleus. Levels tend to have a low-energy
state when they are close to the center of the atom and a higher energy when they
are further apart. Thus, energy is required for an
electron to move to an energy level that’s further from the nucleus. The question is how much?
To work out how much energy is
required to promote an electron from level K to L, we must find the difference
between the two energy levels using the values given. To find the energy difference, we
need to subtract the energy of shell K, which is negative 13.6 energy units, from
the energy of shell L, which is negative 3.4 energy units. Negative 3.4 energy units minus
negative 13.6 energy units gives 10.2 energy units.
Thus, 10.2 energy units are
required for an electron to move from the K level to the L level.
