Video Transcript
The diagram shows a helium
atom. One of the electrons in the first
energy level absorbs a particle and moves to the second energy level. What kind of particle is absorbed
in this process?
This diagram shows us an atom
consisting of a nucleus and two electrons. One of the electrons has moved from
the first energy level up to the second energy level. We need to work out what kind of
particle the electron must have absorbed in order for this to occur.
As the name suggests, an electron
energy level is an indicator of how much energy an electron in an atom has. An electron in the first energy
level will have the lowest possible amount of energy. An electron in the second level
will have greater energy than an electron in the first, and an electron in the third
level has more energy than an electron in the second level.
If an electron absorbs a particular
kind of particle, called a photon, it is possible for the electron to move to a
higher energy level. When this occurs, the electron is
said to be excited.
To understand why this happens, we
need to think about what a photon is. A photon can be thought of as a
packet of energy. When the electron absorbs a photon,
the photon’s energy is transferred to the electron and the energy of the electron
increases. This can only happen if the energy
of the photon is exactly equal to the difference in energy between two energy levels
of the atom.
In this question, we’ve been given
a diagram which shows an electron being excited from the first energy level to the
second energy level. In order for this to happen, the
electron must absorb a photon of the correct energy. This is all we need to know to
answer this question. The kind of particle that is
absorbed in this process is a photon.
