1. The AtomThe Atom
• Smallest piece of matter
that’s still matter
• “Building blocks” of the
universe
• Atoms are the “Lego's” of the
universe

2. The AtomThe Atom
• All matter is made out of
atoms
–Solids, liquids, gasses

6. Its PartsIts Parts
Protons
Positively
charged (+)

7. +
+
+ o
oo o
-
-
-
Proton (+)

8. Its PartsIts Parts
Neutrons
Neutral charge
(o)

9. +
+
+ o
oo o
-
-
-
Proton (+)
Neutron (o)

10. Its PartsIts Parts
Protons and neutrons are
tightly packed together in
the nucleus- the center of
the atom
Most of the mass of an
atom is in the nucleus

11. +
+
+ o
oo o
-
-
-
Proton (+)
Neutron (o)
Nucleus (+)

12. Its PartsIts Parts
ElectronsElectrons
Negative charge (--)
Very small, and have
almost no mass
ElectronsElectrons are found outside
the nucleus

13. +
+
+ o
oo o
-
-
-
Proton (+)
Neutron (o)
Electron (-)
Nucleus (+)

14. Its PartsIts Parts
 Most atoms have the same
number of protons as electronselectrons
 The no. of (+) = the no. of (-)
 Charges cancel each other
 The whole atom has no charge