What's

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What's the matter?
ATOMS
Mrs. Melaney Beauvoir Elementary School Biloxi MS

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What is an atom? An atom is the smallest particle
into which an element (such as gold) can be
divided and still maintain its properties. No
matter how many pieces you divide it into, and
how small those pieces are, it is still gold.
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The word atom comes from the Greek
word Atomos means indivisible.
atomos.
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• Atoms are considered to be the building blocks of
  matter because . . .
• all matter is made up of elements, and
• elements are the building blocks of all matter,
  and
• all elements are made up of just one kind of atom.

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Atoms are made up of even smaller
particles. Protons Neutrons Electrons Protons
and Neutrons are found in the Nucleus of an Atom.
Electrons are found outside the nucleus.
nucleus
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PROTONS have a positive charge. They are located
in the nucleus of an atom. All protons are
identical. Atoms are identified by how many
protons are in the nucleus. An atom with 1 proton
is called hydrogen (H). An atom with 8 protons is
called oxygen (O). All atoms of the same elements
have the same number of protons.
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NEUTRONS are also located in the nucleus. They
are electrically neutral. They have no electric
charge. Remember that a proton has a positive
charge. All neutrons are identical. Sometimes
atoms of the same element have different numbers
of neutrons. Because they are neutral, having a
different number of neutrons does not change the
overall charge of an atom. We call these isotopes
atoms of the same element with a different
number of neutrons.
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ELECTRONS are found outside the nucleus of an
atom. They have a negative charge. All electrons
are identical. The number of electrons and how
they are arranged in an atom determines the
chemical properties of the atom.
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The simplest atom is HYDROGEN. In its nucleus,
there is one proton there are no neutrons. All
other atoms have both protons and neutrons in
their nucleus.
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Hydrogen is the lightest element and it makes up
about 90 of the universe by weight. We must have
Hydrogen to survive because it bonds with Oxygen
to form water.
H2O
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We can put hydrogen gas into a balloon. Because
it is lighter than air, the balloon will
float. Hydrogen gas was once used for
transportation in a dirigible. A terrible fire
on the Hindenburg convinced us it was too
dangerous to use it as a fuel source. Dirigibles
(blimps) now use Helium.
The Spirit of Goodyear blimp
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Scientists used to think electrons orbited a
nucleus like planets orbit the sun. Now they
think electrons travel in random paths in areas
around the nucleus called electron clouds. The
energy level of the electron determines the
average distance it is from the nucleus.
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How does an electron stay in its path around a
nucleus? Protons have a positive
charge. Electrons have a negative
charge. Because the opposite charges attract
each other, the electrons are attracted to the
protons, which keeps them in the orbit around
the nucleus.
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Okay, you say atoms are small. Just how small are
they? A typical atom is one ten-billionth of a
meter in diameter! The average nucleus of an
atom is about one million billionth of a meter in
diameter, which is a very tiny fraction of the
size of the entire atom!
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There are more than a million million
billion atoms in a single drop of water!
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Sources http//www.chem4kids.com/
http//www.howstuffworks.com/ ScienceSaurus A
Student Handbook, Great Source Education Group,
Inc, 2002, pp. 255-257.