Video Transcript
The diagram shows five possible
transitions that an electron can make between the energy levels of a hydrogen
atom. Which transition is part of the
Balmer series?
In this question, we are asked to
identify the Balmer series of electron transitions. First, let’s think about the
diagram we’ve been given. The diagram represents the energy
levels of a hydrogen atom. The ground state is energy level
one, at the bottom, and these higher energy levels correspond to excited states. The binding energy values down the
left-hand side tell us how much energy is required to remove an electron in each
energy level from the atom.
Five arrows have been drawn onto
the diagram, each representing an electron transition. This is when an electron moves from
one energy level to another. For instance, this first arrow
represents an electron moving from the third energy level to the second energy
level. This second arrow shows an electron
moving from the fourth energy level to the first energy level, or the ground
state.
To answer this question, we need to
work out which of these five arrows represents a transition that is part of the
Balmer series. Recall that the Balmer transition
series refers to any transition where an electron in a hydrogen atom moves from a
higher energy level down to the second energy level. The electron might move from the
third, fourth, or fifth energy level. It doesn’t matter where it starts,
so long as it transitions down to the second energy level from a higher level.
If we look at the diagram we’ve
been given, we can see that only one arrow represents a transition to energy level
two, arrow I. This arrow represents an electron
that starts in the third energy level and transitions down to the second energy
level. Since the electron is moving from a
higher energy level down to the second energy level, it is part of the Balmer series
of transitions. So, the transition that is part of
the Balmer series in this question is represented by arrow I.
