After
reading this section you will be able to do the following:
Describe
the behavior of electrons in an atom.
Explain
how electrons allow atoms to gain or lose energy.
So
far, we have talked mainly about what is inside the nucleus of
an atom. Protons and neutrons are found in the nucleus. Circling
around outside the nucleus are tiny little particles called electrons.
Electrons have a negative charge. Electrons spin as they circle
the nucleus billions of times every second. They are moving so
fast and the path that they travel is not the same each time,
so that if we could see these electrons, they might appear to
look like a cloud around the nucleus.
According to current theory, electrons
are arranged in energy levels around the nucleus. When electrons
gain or lose energy, they jump between energy levels as they are
rotating around the nucleus. For example, as electrons gain energy,
they might move from the second to the third level. Then, as they
lose energy, they might move back to the second level or even
to the first energy level. Only a certain number of electrons
can be in an energy level at the same time.
The photon shown in
the graphic can be considered a small bundle of energy
(For
more information on atoms, you may want to review the materials
on magnetism.)
Review:
Electrons
spin and rotate around the outside of the nucleus.
As the
electrons circle the nucleus they travel at certain energy levels
but can "jump" between different energy levels if
they gain or lose energy.
So
far, we have talked mainly about what is inside the nucleus of
an atom. Protons and neutrons are found in the nucleus. Circling
around outside the nucleus are tiny little particles called electrons.
Electrons have a negative charge. Electrons spin as they circle
the nucleus billions of times every second. They are moving so
fast and the path that they travel is not the same each time,
so that if we could see these electrons, they might appear to
look like a cloud around the nucleus.