#### Transcript L3-Sept.9-periodic table

```Question(s) of the Day Rules
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You must work alone
You may use your textbook today
You have 5 minutes to complete the
QOD
Good luck!!
Questions of the Day
Read pages 11-13 of the text then look at the
illustration below. Each letter corresponds to an
observation made by Rutherford. Describe each
observation and match it with one of Rutherford’s
conclusions.
AA
C
B
AA
CC
B
A:
These particles are not deflected. Rutherford concluded
that most of an atom is empty space.
B:
These particles are strongly deflected. Rutherford
concluded that the atom contains a very small, dense nucleus.
C:
These particles bounce back. Rutherford concluded
that the nucleus of the atom is positive.
Rutherford Experiment
What are we doing Today?
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Hand in Timeline
Question(s) of the day
Quiz
Notes/powerpoint
Workbook questions
Go over a few questions
Periodic Table of Elements
The most abundant element in the
earth’s crust is oxygen.
Key to the Periodic Table
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Elements are organized on
the table according to their
atomic number, usually
found near the top of the
square.

The atomic number
refers to how many
protons an atom of that
element has.
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For instance, hydrogen
has 1 proton, so it’s
atomic number is 1.
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The atomic number is
unique to that element.
No two elements have
the same atomic
number.
What’s in a square?
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Different periodic
tables can include
various bits of
information, but
usually:
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atomic number
symbol
atomic mass
state of matter at room
temperature.
Questions?
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What is the most
abundant
element in the
earth’s crust?
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What is the most
abundant
element in the
atmosphere?
Atomic Number
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This refers to how
many protons an
atom of that
element has.
No two elements,
have the same
number of protons.
Atomic Mass
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Atomic Mass refers
to the “weight” of
the atom.
It is derived at by
of protons with the
number of
neutrons.
This is a helium atom. Its atomic mass is 4
(protons plus neutrons).
What is its atomic number?
Valence Electrons
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Valence electrons are the
electrons in the outer
energy level of an atom.
These are the electrons
that are transferred or
shared when atoms bond
together.
Atom
What is the difference between
atoms and elements?
Ice Cream Story
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element - a basic substance that can't
be simplified (hydrogen, oxygen, gold,
etc...)
atom - the smallest amount of an
element
molecule - two or more atoms that are
chemically joined together (H2, O2,
H2O, etc...)
compound - a molecule that contains
more than one element (H2O,
C6H12O6, etc...)
What's wrong with the ice
cream analogy?
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Splitting an atom creates different elements (split an
oxygen atom and you don't have oxygen any
longer). Splitting a scoop of ice cream results in
smaller blobs of the same flavor. For the analogy to
hold true, the flavor of the ice cream would have to
change when you split a scoop (the chocolate
'element' would have to change into some other
'element' (flavor)).
Properties of Metals
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Metals are good conductors
of heat and electricity.
Metals are shiny.
Metals are ductile (can be
stretched into thin wires).
Metals are malleable (can
be pounded into thin
sheets).
A chemical property of
metal is its reaction with
water which results in
corrosion.
Properties of Non-Metals
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Sulfur
Non-metals are poor
conductors of heat and
electricity.
Non-metals are not
ductile or malleable.
Solid non-metals are
brittle and break
easily.
They are dull.
Many non-metals are
gases.
Properties of Metalloids
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Silicon
Metalloids (metal-like)
have properties of both
metals and non-metals.
They are solids that can
be shiny or dull.
They conduct heat and
electricity better than nonmetals but not as well as
metals.
They are ductile and
malleable.
Classwork
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Finish Workbook pages 3 & 4
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