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Stars - Life Cycle - Birth - Fusion (continued).
Fusion releases
large amounts of energy.
Where does the energy come
from?
If you
add up the mass of the nuclei
before and after fusion,
you find that some mass has
gone missing.
The process of fusion destroys a
little bit of mass.
This little bit of mass turns into a large
amount of energy.
The process
of fusion (nuclei joining together) continues in stars
eventually making bigger and
bigger nuclei.
After helium with two protons,
lithium can form with three protons,
then beryllium with four protons and so
on.
The larger nuclei are called "heavier elements".
Older stars which have used
up most of the original hydrogen
start making the heavier elements.
Uranium and other
heavy elements are present
in the core of the Sun
and the rocks of the planets in our solar system.
The Sun is not old enough to
have made uranium.
This is evidence that the Sun and the planets
formed from the remains of a
previous supernova.
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Copyright © 2008 Dr. Colin France. All Rights Reserved.