The Atom
Matter
• Is anything that has weight
and takes up space.
• All matter is made of atoms.
Atom
Since the atom is too
small to be seen
even with the most
powerful
microscopes,
scientists rely upon
models to help us
to understand the
atom.
Believe it or not this is a
microscope. Even with the
world’s best microscopes we
cannot clearly see the
structure or behavior of the
atom.
Atom
 The smallest particle of an element that
has the properties of that element.
 Made of:
 Nucleus (center of atom)
 Protons
 Neutrons
 Electrons
Nucleus
Protons
 Large mass compared to electrons
 Positive Charge
 Located in the nucleus (center)
Neutrons
 About the same size as protons
 No electrical charge= neutral
 Located in the nucleus
Electrons
 Very small compared to protons and
neutrons.
 Negative Charge
 Located in orbital shells surrounding the
nucleus.
The Atom
Orbital shells
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
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s
p
d
f