Transcript The Periodic Table - Woodhaven High School

The Periodic Table
Proposed by Mendeleev
Dmitri Ivanovich Mendeleev
1834-1907
Born in Siberia, the last
of at least 14 children,
Dmitri Mendeleev
revolutionized our
understanding of the
properties of atoms and
created a table that
probably adorns every
chemistry classroom in
the world.
Arrangements
• Periods – Rows – determines the number
of energy levels in an atom
– Lanthanide Series (57-71) – rare earth
elements
– Actinide Series (89-109) – radioactive
elements
Lanthanide Series – Rare Earth Elements
-Not as rare as once thought
-The lanthanides have many scientific and industrial uses. Their
compounds are used as catalysts in the production of petroleum and
synthetic products. Lanthanides are used in lamps, lasers, magnets,
phosphors, motion picture projectors, and X-ray intensifying screens.
Lanthanum
Cerium
Actinide Series - Radioactive
They are all radioactive and some are not
found in nature. Some of the elements with
higher atomic numbers have only been made
in labs.
Arrangements (cont.)
• Groups or Families – arranged according
to the number of electrons in the outer
energy level
– IA or 1 – alkali metals
– IIA or 2 – alkali earth metals
– VIIB or 17 – halogens
– VIII or 18 – noble gases – inert gases
Alkali Metals
.
-Very reactive
-One electron in the outer shell
-Shiny
-Light weight
Alkali Metals Properties
• Very reactive
– Explode when exposed to water
•
•
•
•
•
Do not occur in nature
One electron in outer shell
Softer then most metals
tarnish rapidly even in dry air
good conductors of heat and electricity
Sodium
Alkaline Earth Metals
So we just
.
-Two electrons in the outer shell
-Fairly reactive (not as reactive as Alkali metals
Properties of Alkali Earth Metals
• Have an oxidation number of +2
• Very reactive
–Not as reactive as Alkali metals
•
•
•
•
Not found in nature
Two electrons in outer shell
Soft metal
Low-density
Magnesium - Mg
Magnesium tarnishes
slightly in air, and finely
divided magnesium readily
ignites upon heating in air
and burns with a dazzling
white flame. Normally
magnesium is coated with a
layer of oxide, MgO, that
protects magnesium from air
and water.
The Halogens
They have seven electrons in their outer shell. They are all
just one electron shy of having full shells. Because they are
so close to being “happy”, they have the trait of combining
with many different elements. You will often find them bonding
with metals and elements from Group One of the periodic
table.
Halogens
The Halogens are a generally nasty
bunch. Think toxic choking fumes. But in
compounds with the similarly strongwilled alkali earths, they can be delicious.
F
Fluorine
Halogen Properties
•
•
•
•
•
Non-metallic
“halogen” meaning “salt-former”
Have 7 electrons in their outer shell
Oxidation number of -1
At room temperature, exist in a solid,
liquid, and gas form
Inert Gases - Noble Gases
All of the inert gases have full outer shells with eight electrons.
Oh wait! That's not totally correct. At the top of the inert gases
is little helium (He) with a shell that is full with two electrons.
The fact that their outer shells are full means they are quite
happy not reacting with other elements.
Properties of the Noble Gases
• Oxidation number of 0
• Have maximum number of electrons in
outer shell
• Stable
• unreactive
Metals vs Nonmetals
Metalloids