Transcript What good is the Periodic Table?

What good is the
Periodic Table?
There is a table provided for your use
during the TAKS test, what can it do to
help you?
What is an element?
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Basically, if it is listed anywhere on the
periodic table (of the elements) it is an
element.
If it is on the left side it is a metal element, if it
is on the right side it is a NONmetal element.
(Hydrogen is the ONLY nonmetal to the left of
the stairstep line.)
Let’s look . . .
Where are the metal elements?
Left of the Stair-step line!
Where are the nonmetals?
To the Right of the stair step line, and Hydrogen!
Where are the metalloids?
Along the stair
step line.
These
elements have
properties of
both metals and
nonmetals.
The center elements on the table are called the transition
metals. Many of them have more than 1 way they will give
away electrons, so they change, or transition, ion charges. The
charge these metals use are given by a roman numeral in the
name. (Iron (II) chloride)
The Rare Earth Metals are radioactive and form
the bottom 2 rows, also called the Lanthanide
and Actinide Series.
So, I can tell if it’s a metal or not, what
else?
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Each column on the table is a group or family
of elements that have similar chemical
properties.
They form the same types of compounds, in
the same ratio.
They have the SAME NUMBER OF OUTER
SHELL (valence) electrons.
Lets look . . .
Group # 18 is the family called Noble Gases – each one
has 8 outer shell electrons (full shell) so they don’t form
compounds.
Group #1 is called the Alkalai metals, they have
1 valence electron, and will form +1 ions. The are
Alkalai because they form the strongest (highest
pH) bases.
Group #2 is called the Alkalai Earth Metals and they
have 2 valence electrons, which they will give away to
form +2 ions.
Group #17 are the Halogens, they all have 7 electrons
in their valence shell, and want to have 1 more when
they form compounds. They all become -1 ions when
they can.
For each group, they form compounds the
same way, for example. . .
Beryllium forms a compound with Cl in the
ratio of 1:2 or BeCl2
 Since Mg and Ca are in the same family or
group, they will form the same type of
compounds in the same ratio.
 MgCl2 and CaCl2
 This is what is meant when they have
“similar chemical properties”
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Each square also tells us information
about each element.
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The 1 or 2 letters that
represent the element
are its symbol.
The number at the top
of the square is the
atomic number.
The numbers at the
bottom of the square is
the average atomic
mass.
What do the numbers mean?
11
Na
22.990
sodium
This is the atomic
number. It is the number
of protons in a single
atom of this element. By
the way, its also # of
electrons.
The symbol for this element.
This is the atomic mass, it is
the number of protons +
neutrons, or the mass of the
nucleus of an atom.
This is the name of the element.
Use the table, it will help you answer at
least 5 questions!
That may be the difference you need to pass!!
Now, let’s write some
formulas and names
1.
2.
3.
4.
Roll one of each color, the positive ion is
written first.
Use the charge as the subscript to the
opposite ion, but remove the + or --.
If the ion is a group, DO NOT CHANGE
THE GROUP, put it in ( ) with the
number as a subscript outside.
To name it, write the name of the + ion,
then name the – ion, or if it is an
element, change the ending to –ide.
Don’t forget the Roman Numeral for
transition metals.
Law of Conservation of Mass
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Matter can not be created
or destroyed.
This means if it is on one
side of an equation, it
must be on the other, and
there must be the same
number of atoms of that
element.
Thanks for coming . . .
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Next week:
Monday – Math in Room 593
Tuesday – Using formula
charts and calculators with
Test Taking Tips in the
Teaching Theater
Wednesday – Science help
here in Room 150