Video Transcript
An electron that is part of an atom
has the minimum energy possible for electrons in that atom. Is the electron in an excited
state?
To answer this question, let’s
first recall that electrons in atoms can occupy different energy levels, or
states.
For example, let’s think about a
hydrogen atom, which only has one electron. The electron in this atom can
occupy one of many different energy levels. We can represent these energy
levels like so. This level right at the bottom
represents the minimum possible energy for an electron in the atom. This energy level is called the
ground state. Each of these higher-up levels
corresponds to a greater and greater energy. These levels are called excited
states. Remember, too, that an electron’s
energy must correspond to a certain state; it’s not possible for an electron’s
energy to be in between levels.
Now, this question is asking us
whether an electron that has the minimum possible energy in an atom is in an excited
state. To represent this electron, we can
add it onto our energy level diagram. We know that the electron has the
minimum possible energy, which means it must occupy the lowest possible energy
level. That’s the very bottom level in the
diagram.
So, the electron is here, in the
ground state, because it has the minimum possible energy. When an electron is in the ground
state, it is not in any of the excited states. It is possible for a ground-state
electron to move up to an excited state if energy is transferred to it, but that’s
not what’s happening in this question.
So, we have seen that an electron
that has the minimum possible energy in an atom must occupy the ground-state energy
level. Therefore, the answer to this
question is no, the electron is not in an excited state.
