Transcript What good is the Periodic Table?

What good is the
Periodic Table?
A Periodic Table is provided for
your use during the TAKS test.
What can it do to help you?
What is an element?
•Basically, if it is listed anywhere on the periodic
table, 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?
To the Left of the Stair-step line!
Where are the nonmetals?
To the Right of the stair step line, including 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
compound name. (Iron (II) chloride)
The Rare Earth Metals are radioactive
and form the bottom 2 rows, also called
the Lanthanide and Actinide Series.
Now, I can tell if it’s a metal or not.
What else do I need to know?
• 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.
Each group forms 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.”
Each square also tells us
information about each element.
• 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 name of the
element.
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 in a
neutral atom.
This is the symbol for this
element.
The atomic mass is the number of
protons PLUS the number of
neutrons, or the average mass of
ALL sodium isotopes. An isotope
has the same atomic number but a
different atomic mass because
the isotope has a different
number of neutrons.
Use the table, it will help you
answer at least 5 questions!
It may be the difference you need to pass!!
Now, let’s write some formulas and names…
1.
2.
3.
4.
5.
6.
7.
Elements from opposite sides of the Periodic Table
will form IONIC bonds (opposite sides = opposite
charges).
Elements from the Non-metals will form COVALENT
bonds.
The + ion (from the Left side) is ALWAYS written
first and followed by the – ion (from the Right
side).
When the ions have different charge numbers (Na+1
& O-2), use the charge number as the subscript for
the opposite ion, but remove the sign (Na2O) (sodium
oxide).
Polyatomic ions include NH4+1 & PO4-3. When writing
them in a formula, the charge is written as a
subscript outside the ( ) (NH4)3PO4…ammonium
phosphate.
To name the compound, write the name of the + ion
first, then the name of the – ion, and change the
ending to –ide for elements & -ate/-ite when O is
present in a polyatomic ion PO4-3 (phosphate).
Transition metals use a Roman Numeral in their
names for their charge.
Copper (l) chloride = Copper (l) = (Cu+1) chloride (Cl-) = (CuCl).
Copper (ll) chloride = Copper (ll) = (Cu+2) chloride (Cl-) (CuCl2).
Law of Conservation of Mass
• 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 participating . . .
Remember…it’s all
elemental!!!