After
reading this section you will be able to do the following:
List the
three main subatomic particles of an atom.
Discuss
the positions of these particles within the atom and what electric
charge they carry, if any.
What are atoms
made of?
Now that we have talked about how
atoms are combined to make other substances, let's talk about
the particles that make up the atom. Particles that are smaller
than the atom are called subatomic particles. The three main subatomic
particles that form an atom are protons, neutrons,
and electrons. The center of the atom is called the nucleus.
First, let's learn a bit about protons and neutrons, and then
we will talk about electrons a little later.
Protons and Neutrons
Protons and neutrons make up the nucleus
of an atom. All protons are identical to each other, and all neutrons
are identical to each other. Protons have a positive electrical
charge, so they are often represented with the mark of a "+"
sign. Neutrons have no electrical charge and are said to
help hold the protons together (protons are positively charged
particles and should repel each other).
If all protons are identical and all
neutrons are identical, then what makes the atoms of two different
elements different from each other? For example, what makes a
hydrogen atom different from a helium atom? The number of protons
and neutrons in the nucleus give the atoms their specific characteristics.
In the graphic below you will notice that each of the three elements
have different numbers of protons and neutrons. They would also
like to have the same number of electrons as they have protons
in order to stay electrically balanced.
Review:
Subatomic
particles are particles that are smaller than the atom.
Protons,
neutrons, and electrons are the three main subatomic
particles found in an atom.
Protons
have a positive (+) charge. An easy way to remember this is
to remember that both proton and positive start
with the letter "P."
Neutrons
have no electrical charge. An
easy way to remember this is to remember that both neutron
and no electrical charge start with the letter "N."
