First 171 words of the document:
Let's say an atom is missing a neutron or
has an extra neutron. That type of atom is
called an isotope.
An atom is still the same element if it is
missing an electron. The same goes for
isotopes. They are still the same element.
They are just a little different from every
other atom of the same element.
There are a lot of carbon atoms in the
universe. The normal ones are carbon12.
Those atoms have 6 neutrons. There are a
few atoms that don't have 6. Those odd
ones may have 7 or even 8 neutrons.
Carbon14 actually has 8 neutrons (2
extra). C14 is considered an isotope of the
When you look at the periodic table you
notice that the atomic mass of an element
is rarely an even number. That happens
because of the isotopes. They take the
number in the middle of the pair.