Transcript Atoms ppt. - Warren County Public Schools

Elements & Atoms
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An atom refresher
• Matter is anything that takes up space and has
mass.
• All matter is made of atoms
• Atoms are the building blocks of matter, sort of
how bricks are the building blocks of houses.
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An atom refresher
• An atom has three parts:
• Proton = positive
• Neutron = no charge
• Electron = negative
• The proton & neutron are
found in the center of the
atom, a place called the
nucleus.
Picture from
http://education.jlab.org/qa/atom_model_03.gif
• The electrons orbit the
nucleus.
Created by G.Baker
www.thesciencequeen.net
What are molecules?
• Elements are the
alphabet to the language
of molecules.
• Molecules are electrically
neutral groups of two or
more atoms bonded
chemically.
• Elements are made of
atoms. While the atoms
may have different
weights and organization,
they are all built in the
same way.
Created by G.Baker
www.thesciencequeen.net
Graphic from http://education.jlab.org/atomtour/fact2.html
Created by G.Baker
www.thesciencequeen.net
More about Elements..
• Elements are the building
blocks of all matter.
• The periodic table is a list
of all of the elements that
can build matter. It’s a little
like the alphabet of
chemistry.
• The periodic table tells us
several things…
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Periodic Table
Atomic Number:
Number of protons
and it is also the
number of electrons
in an atom of an
element.
Element’s Symbol:
An abbreviation for
the element.
Elements Name
8
O
Oxygen
Atomic Mass/Weight:
Number of protons +
neutrons.
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16
Electrons have special rules….
• You can’t just shove all of the electrons into the
first orbit of an electron.
• shells or energy levels- where electrons
orbit around the nucleus of an atom.
• Only a certain amount of electrons can be in
one shell.
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Nucleus
1st shell
2nd shell
3rd shell
The electrons in the outer most shell of any element are
called valance electrons.
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All of the Elements are arranged
in a table called the ...
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Each section is special…
• The first two groupings are the metals and
nonmetals
• They are then broke down into even smaller
groupings based on their properties. (seen
below)
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• Metals
•Very reactive metals
•Good conductors of heat and electricity
•Nonmetals
•Very brittle
•Not able to conduct electricity or heat very well
•At room temperature they exist in 2 states of matter
gases and solids.
Lets look at an individual
element…
Protons = 3
3
Li
-
+
-
Lithium
7
+ +
-
Atomic mass = 7
So, (7-3=4)
Electrons = 3
2 in the 1st shell, 1 in the 2nd shell
4= number of
neutrons.