2. Matter
The term matter
describes all of the
around us.:
physical substances
Your table,
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
your body,
a pencil,
water,
THE UNIVERSE.
Matter has mass and takes up space (volume).
It is made up of different kinds of atoms.
3. Matter includes things that can be
seen,
tasted,
smelled,
TIFF (U QuickTime™
nco
and
are need mpressed) decom a
ed to see
this pictupressor
re.
or touched.
Matter does not include heat, sound, or light.
4. QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
What is matter made of?
5. Models are for things that are too small or too large.
Models explain data or facts. So, they are theories.
6. Modern Model of the Atom
The Electron Cloud
Is sometimes called the
wave model.
Has a spherical cloud of
varying density.
Varying density shows
where an electron is
more or less likely to be.
7. What do we now think atoms are made of?
Protons:
•Are much larger and heavier than electrons.
•Have a positive charge (+).
•Are located in the nucleus.
Electrons:
•Are tiny, light electrical particles that are negative (-).
•Move around the outside of the nucleus.
Neutrons:
Are large and heavy like protons.
Have no electrical charge.
Are located in the nucleus of the atom.
8. An Atom is a Basic Building Block,
so it’s an Element!
Each element has a different number
of protons.
The number of protons is also called
proton
the atomic number.
So,
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
atomic # = # of protons
The atomic #= Fingerprint
9. •Every _______
has its own
atomic number.
QuickT
TIFF (
Un
im
are neecompressed e™ and a
)d
ded to
see thisecompresso
r
picture
.
10. So what’s with atomic mass?
Imagine trying to measure
the mass of something so small
that you cannot see it!
Scientists use the amu,
or atomic mass unit,
to measure mass.
TIF
F
are (Unc Quic
n e e o mp k T
ded res ime
to s sed) ™ a
ee dec nd a
this om
pic pre
tur sso
e.
r
One amu = the mass of one proton and neutron,
but the electron is so small, it is 1/1,836 amu!
So, cut out the electron in the calculation:
the mass of protons + neutrons = atomic mass.
11. How are atomic mass and atomic
number different? Does it matter?
The atomic number can be found above
the element’s name on the periodic table.
It is the number of protons.
and
The atomic mass is both the
TIFFQuickTime™ this
(Uncompressed)
are needed to see
protons and the neutrons
together.
Round it..
Atomic mass - Atomic number = the # of neutrons.
If you know one of the three numbers, can you figure
out the others?
12.
13. If Element = Different Atomic Mass than says on
Periodic Table, it’s Called Isotope
The atomic number of an element
never changes. This is its
fingerprint.
But, atoms of the same element
may not all have the same number
all have the same number
of neutrons.
This means that these atoms may
have a different atomic mass.
14. Isotope :
An Element that Has a Different Atomic Mass
than What Appears on the Periodic Chart.
It Even Has a Different Name.
Isotopes = Element Variations
15. If an isotope has a different atomic masses,
and you know its atomic number,
what can you figure out ?
TIF
F
are (Unco Quic
nee mp kTi
ded res me™
to s sed)
ee dec and a
this om
pic pres
tur sor
e.
If a nucleus has too many
or too few neutrons,
it becomes unstable.
It releases radiation and decays.
This means the electrons
can be broken down and released.
Mass # - Atomic # = # of Neutrons
16. Carbon-14 dating, or radiocarbon
dating, uses the amount of carbon-14
in a substance to calculate its age.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
17.
18. Ions are
Atoms Seeking Balance
An atom that carries an electrical
charge is called an ion.
If the atom loses electrons, the atom
becomes positively charged (more
protons = + charge). What if it gains
electrons? (more electrons = - charge)
19. Ions Seek Partners
Helium Atom
Hint:
All electrons have a negative
charge.
charge
How is this ion positive?
How is this ion negative?
