Transcript The Periodic Table

The Periodic Table
Dmitri Mendeleev - 1869
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Mendeleev was born in Siberia, Russia
in the year 1834. He died in 1907
He was a professor of Chemistry at the
St. Petersburg University. Trying to
explain to his students how elements
had similar properties, he started
organizing the elements into rows and
columns
He observed that some elements have
similar chemical & physical properties
The first periodic table was organized by
atomic mass
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The masses were compared to
Hydrogen, the lightest known element at
the time.
The modern Periodic Table is organized
by Atomic number
Organizing the Elements
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The periodic table is laid out by increasing atomic number as you go across and down the table
Atomic # increases 
Atomic # increases 
Periods, Groups & Families
Groups & Families are in vertical columns, there are 18
Periods are
Rows
Groups
There are 7 numbered Periods and 18 numbered
Groups
Families are named in 2 ways, 1st after
the top element in the column, The Oxygen Family contains O, S, Se,
Te & Po.
2nd way to name them is w/ their “old
fashion” names. (see next slide)
“Need-to-Know Families
“Old Fashion Names” of certain Families
Alkali Metals
Alkaline Earth Metals
Noble Gases
Halogens
Chalogens
More Need-to-Knows
Transition Metals
Actinides
Lanthanides
Rare Earth Elements – AKA Inner Transition Metals
Parts of an Atom
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An atom consists of a nucleus surrounded by one or more electrons
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Atoms are electrically neutral w/ the same number of protons
as electrons.
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Majority of the atom is empty space. If nucleus were the size of a
pencil eraser, the closest electron would be 100 yards away!
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Subatomic Particles
– Protons
– Neutrons
– Electrons
Parts of an Atom
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Subatomic Particles
– Protons
– Neutrons
– Electrons
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Nucleus: Tightly packed
Protons & Neutrons
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Electrons Orbiting nucleus
@ 1 % speed of light!!
Atomic Number
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By definition:
The Atomic Number = the number of Protons
present in the nucleus of an atom
Each Element in the Periodic Table has a different
number of Protons, therefore each element has a
different, unique, atomic number.
Atomic Number
When reading the Periodic table, notice each element has a
unique 1 or 2 letter symbol and “big” & “small” number listed
“Small” number is always
the Atomic Number,
therefore the number of
protons present
“Large” number is always
the Atomic Mass which
tells us the total # of both
Protons & Neutrons
present
Atomic Mass
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How much does an atom “weigh”?
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What is the mass of an atom?
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SI Unit for mass is the Gram…. Way toooo big to
accurately “mass” an atom
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Came up w/ new unit, an AMU (atomic mass unit)
1 AMU = mass of 1 Proton
Atomic Mass
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mass of subatomic particles
– Proton = 1 AMU
– Neutron = 1 AMU
– Electron = .0005 AMU
Atomic Mass = the total # of both Protons &
Neutrons in the atom
– ( we don’t worry about the mass of the electrons
since they have almost no mass)
How many Neutrons are there?
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Remember:
– The Atomic # = the # of Protons
– The Atomic mass = The # of both Protons &
Neutrons.
– Therefore, if you subtract the Atomic # (the number
of Protons) from the Atomic mass (the number of
both Protons & Neutrons) what is left over must be
the number of Neutrons!!
How many Neutrons are there?
For Example w/ Carbon:
Atomic Mass-Atomic # = #
Neutrons
Atomic Mass = 12,
Atomic # 6
12 – 6 = 6
Therefore there are 6 neutrons
present in the Carbon nucleus
If you don’t believe
me… just count for
yourself.
Electrical Atomic Charge
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Electrical charge – all atoms have a neutral charge
– ( a zero net electrical charge)
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Protons have a positive (+) electrical charge
Neutrons have a neutral (0) electrical charge
 Electrons have a negative (-) electrical charge
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Since the net electrical charge is 0 (neutral), if you have 10 Protons (10 “+”
charges) then there must be 10 “-” charges (10 electrons) present to
balance out the atom.
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Therefore, as long as you know the Atomic #, you know the # of Protons
and also the # of Electrons!!
The Alkaline Earth Metals – Group 2
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not as reactive as Alkali Metals, but still
very reactive. They have two valence
electrons and generally give them up to
nonmetals to form ionic bonds. Examples
include Calcium and Magnesium
The Alkali Metals – Group 1
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Very reactive metals that have only one
valence electron in the outer orbit and
will freely give it away to become stable.
Very soft metal (you could cut it w/ a
plastic knife!). They form ionic bonds w/
Halogens and Chalogens. Examples
include Sodium and Potassium.
Noble Gases - Group 18
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Non reactive, have a full compliment of
valence electrons, 8 and are called the “Inert
Gases” because they do not react w/ other
elements. Examples include Helium (very low
mass and is used in filling children’s balloons
and even airships and the “Goodyear Blimp)
and Neon used in lighted bulbs to make a red
glowing light ( a neon light).
Halogens – Group 17
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Very reactive nonmetals w/ 7 valence electrons.
Need only one more electron to fill their outer
shell. Will steal an electron from a reactive metal
to form ionic bonds. Examples include Fluorine (
the most reactive nonmetal), Chlorine (the most
abundant halogen), Iodine and Bromine (found
in Seawater).
Chalogens AKA:
Oxygen Family – Group 16
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nonmetals w/ 6 valence electrons, need 2
electrons to fill the outer shell. Oxygen’s most
common oxidation state is -2. Examples are
Oxygen (ozone is one of its allotropes),
Sulfur (responsible for that rotten egg smell
when it combines w/ oxygen to form sulfur
dioxide) and Selenium (one of the few non
metals that are also a good conductor of
electricity).
The Nitrogen Family–
Old Group VA ,new Group 15
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These elements have 5 valence electrons
Include Nitrogen – most abundant gas in
the atmosphere
Phosphorus – has allotropes that are Red
and White
Bismuth – the metal used in automatic
sprinklers because of its low melting point
Arsenic – a poisonous element used in
medicine and even rat poison.
Transition Metals –
Groups 3 thru 12
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These all vary dramatically in reactivity, Their oxidation
states (# of valence electrons) vary. They are a bridge
between the very reactive Alkali and Alkaline Earth
Metals and the nonmetals.
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Most of the elements are Metals
Examples include: Iron, Bismuth, Tin, Sodium, Calcium, Gallium,
etc.
Bismuth – used in automatic sprinklers
Gallium - has an oxidation number +3
Cobalt – A metal w/ more than one oxidation state
Metals tend to form positive (+) ions.
Most Metals form Ionic bonds w/ nonmetals.
Physical Properties
– Such as hardness, shiny, malleability (pounded into shapes),
– ductility (stretched or pulled into a wire) electrical conductivity and
magnetic.
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Chemical Properties
– Metals show a wide range of chemical properties.
17 Nonmetals
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a. There are 17 nonmetals, each are located to the right of the
zigzag line in the periodic table.
b. Phosphorus – has Common allotropes of Red & white
c. Selenium – nonmetal that is a “good conductor”
Non metals tend to steal electrons when they form negative (-) ions.
c. Physical Properties – in general, the physical properties of
nonmetals are opposite those of metals. Powdery, gaseous, crumbly,
non conductive, dull, not ductile or malleable.
d. Chemical properties – usually form ionic bonds when combined
w/ metals (NaCl, FeO2, and CaCl2 ) and usually form covalent bonds
when combined w/ other nonmetals (CO2, O2, C6H12O6)
– Asbestos – substance once used for its fire retardant characteristics but is
no longer used because of it’s a carcinogen.
– Carbon – the element on which all life is based.
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e. Even though Hydrogen (H) is located in
Group 1, it is still a nonmetal and exhibits
oxidation states of +1 and -1.
Nonmetals are the
light blue elements
Metalloids
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AKA “semi metals”
7 elements on the zigzag border between metals and the non
metals.
Their properties will sometimes make them act like a metal and
then sometimes act like a nonmetal.
Most important characteristic is their varying ability to conduct
electricity. Silicon is used to make Semiconductors which are
used in making computer chips.
“Need-to-Know” Elements
Remember: Atomic Mass – # of Protons = # of Neutrons
Remember: Atomic # = # of Protons & also # of Electrons
Where do we find elements on the
Earth
CAR-BON
This is the magic element for everything on Earth. All life on Earth depends
on carbon (C). It is in nearly every biological compound that makes up our
bodies, systems, organs, cells, and organelles. When you breathe out, there
is a lot of carbon dioxide (CO2). Carbon has been known and used for
thousands of years. It was never really discovered. Ancient people knew of
the black soot left over after a fire. That was carbon.
Carbon is the sixth element in the periodic table. Located between boron (B)
and nitrogen (N), it is a very stable element. Because it is stable, it can be
found both by itself and in many naturally occurring compounds. Scientists
describe the three states of carbon as diamond, amorphous, and graphite. It
is the same graphite you find in pencils.
Plants
All plants have c
important eleme
would not exist.
on Earth also ne
You can't just ea
in plants before
with it.
Diamonds
When you see a
chunk of carbon
and carbon is le
area, all of the a
together to form
called a diamond
Charcoal
The next time y
barbecue you'll k
ingredient of the
Carbon compou
and is good at h
why it's used for
Graphite
Take a look at y
stuff you write w
is a special type
graphite.
Petroleum Pro
Next time you're
can know that c
important part o
made up of oil a
plants which die
You know there
means there is c
Plastics
Everything that
We just talked a
gasoline, plastic
That means carb
important eleme
Carbon
Plants
All plants have carbon as their most important element. Without carbon plants would not exist. That
means every animal on Earth also needs carbon to survive. You can't just eat carbon, it needs to be
in plants before humans can do anything with it.
Diamonds
When you see a diamond it is one big chunk of carbon. After a very long time and carbon is left in a
very high pressure area, all of the atoms are pushed together to form a crystal. That crystal is called
a diamond.
Charcoal
The next time your family goes to a barbecue you'll know that the main ingredient of the charcoal is
carbon. Carbon compounds store lots of energy and is good at holding onto heat. That's why it's used
for charcoal.
Graphite
Take a look at your pencil. The black stuff you write with is made of carbon. It is a special type of
carbon called graphite.
Petroleum Products
Next time you're at the gas station you can know that carbon is the most important part of gasoline.
Gasoline is made up of oil and oil is created from the plants which died millions of years ago. You
know there is carbon in plants... That means there is carbon in oil and gasoline.
Plastics
Everything that is plastic has carbon in it. We just talked about gasoline. Like gasoline, plastic things
are made from oil. That means carbon is also the most important element plastic.
Nitrogen
The second of the big three elements in row two is nitrogen (N).
Nitrogen is the seventh element of the periodic table. It is located
between carbon (C) and oxygen (O). Along with carbon and oxygen,
nitrogen is essential in most of the compounds that allow life to exist.
It would be great if you remember that nitrogen is an important part
of amino acids. We'll tell you again later, but you should always know
that almost eighty percent of Earth's atmosphere is made of
nitrogen gas.
Even though it surrounds us every day, nitrogen wasn't isolated until
1772 by Daniel Rutherford. It was named eighteen years later by the
chemist Chaptal. Nitrogen is a clear gas that has no smell when it is
in its pure form. It is not very reactive when it is a pure molecule,
but it can create very reactive compounds when combined with other
elements, including hydrogen (H) in ammonia (NH3).
Nitrogen
Ammonia
Nitrogen is in something called ammonia. Your parents might have ammonia around the house
where they use it to clean things. Ammonia is used as a disinfectant because it kills bacteria and
fungus. It is very poisonous... So stay away from it.
Steel Manufacturing
Nitrogen is used in the processes to make steel. Many other elements are also used to make
steel. It is not an easy thing to do. Scientists use nitrogen in many difficult processes.
Coolant
Nitrogen is used as a refrigerant. When it is in a liquid form nitrogen is very cold. Scientists use
that cold nitrogen to keep things frozen.
Oil and Petroleum Refineries
Nitrogen is used to refine oil. Scientists get oil out of the ground but it can't be made into
gasoline without nitrogen.
Atmosphere
Even though we breathe oxygen from the air, did you know that over three quarters of the air is
made up of nitrogen? Let's say you had one hundred pennies. Take 78 pennies and put them to
the side. That's how much nitrogen is in the air.
Soil Nutrients
Plants need nitrogen to grow. They get the nitrogen out of the soil that they grow in. The
nitrogen is sucked in through the roots and pumped all the way up to the leaves. That's a long
way if that tree is fifty feet tall.
Oxygenn
You're breathing right now and your body is taking in oxygen (O)
molecules. You need oxygen to survive, as do almost all other living
organisms. It's a good thing that oxygen makes up over twenty percent of
the Earth's atmosphere. We are the only planet in the solar system with
enough oxygen gas available to let us survive.
Did you know that if you breathe too much oxygen you could die? What
about this: If you have a room filled with oxygen and hydrogen (H) and
someone lights a match... it will explode! That's because oxygen is very
reactive.
Oxygen is the eighth element of the periodic table and can be found in
the second row (period). Alone, oxygen is a colorless and odorless
molecule that is a gas at room temperature. Oxygen molecules are not
the only form of oxygen in the atmosphere; you will also find oxygen as
ozone (O3) and carbon dioxide (CO2). A chemist named Priestly isolated
oxygen in 1774.
Oxygen
Ozone Layer
the past couple of years you may have heard of something called ozone. It is a compound that
floats in the atmosphere around the Earth. Did you know that ozone is made up of oxygen? That's
right. Three oxygen atoms can combine and make ozone.
Plastics
Oxygen is inside things made out of plastic. Every time you get a 2-liter bottle or a yogurt, look at
the plastic. Now you know there is oxygen inside all plastics.
Breathable Air
Oxygen is very important. Life on Earth could not exist without it. Animals need to breathe oxygen
to survive. Luckily, there is enough oxygen in the air for everyone to breathe.
Rocks and Soils
You just read that there is oxygen in the air. Here's something else... 50% of the Earth's crust is
made up of oxygen. That means that no matter what you pick up or dig up from the ground...
There's a good chance that one half of it is made up of oxygen.
Water
Over half of the Earth is covered with water. Mixed in that water is oxygen. In the same way we
breathe the oxygen in the air, fish breathe the oxygen in the water.
Fluorine
Fluorine (F) is the ninth element of the periodic table and was first isolated and
identified in 1886 by a scientist named Moisson. Scientists knew about fluorine
for hundreds of years, but it wasn't isolated until the late 1800s. Now we use
fluorine in refrigerators, toothpaste, and rocket fuels.
Located in the second period of the table (row 2), fluorine is the first element in
the family of halogen gases. Fluorine is a yellowish gas at room temperature
and is very dangerous. Be careful if you are working in a chemistry lab with
fluorine gas. Even though the names rhyme, don't get fluorine mixed up with
chlorine (Cl) in your homework. They are very different elements, and fluorine
is both poisonous and very reactive with other elements. It can combine with
nearly any element on Earth.
Fluorine
Rocket Fuel
Fluorine is used in rocket fuels. Fluorine is a very reactive element which makes it good for very
explosive reactions.
Uranium Purification
Fluorine is used to refine another element called uranium. Uranium is used in nuclear reactors for
fuel. Without fluorine, scientists couldn't get pure uranium.
Refridgeration Fluids
There is something that helps your refrigerator work. It's called Freon. Freon is pumped through a
whole system of tubes. As the Freon moves through your refrigerator, it makes everything cold.
One of the main elements in Freon is fluorine.
Toothpaste
At night when it's time to brush your teeth take a look at your toothpaste. Inside that tube is
fluorine. Scientists put very small amounts of fluorine inside your toothpaste to help make your
teeth whiter.
Etching Solutions
It's very hard to draw something called etched glass. Have you ever seen a really fancy window?
Have you see the foggy white part of the window that makes some kind of pattern? That is etched
glass. Artists use fluorine when they do that to the glass. Ask your parents. Maybe you have some
of that glass at home!
Sodium
As we begin our exploration of the third period (row) of the periodic
table, we find the element sodium (Na). Being in the first column,
sodium is a member of the alkali metal family with potassium (K) and
lithium (Li). Sodium's big claim to fame is that it's one of two elements
in your table salt. When bonded to chlorine (Cl), the two elements make
sodium chloride (NaCl). Sodium is also used as a salt in many fertilizers.
Even though humans have been using sodium for thousands of years, it
was not isolated until 1807 by a chemist named Davy. When you purify
sodium, you actually wind up with a silvery bright metal that is quite
soft and malleable. Sodium is one of the few metals that will float when
it is placed in water (H2O). Sodium's atomic mass is less that water's
atomic mass of 18 amu.
Sodium
Glass Manufacturing
Sodium is used to make glass. You know that silicon makes up most of glass. In the process of making
glass sodium is often used as well.
Paper Manufacturing
The next time you write on a piece of paper you should know that sodium is used to make that paper.
Paper is originally from trees. Before it gets to you a lot of chemicals are used to get it ready. Sodium is
one of the elements used.
Table Salt
When you sit at the table for dinner look for the salt shaker. Sodium and chlorine combine to make salt.
If you look at the salt very closely you can see that they make little crystals. Those crystals look like
little cubes. The shape is partially because of sodium.
Developing Solutions
When your parents send their photographs on film to be developed, the company uses different liquids
to make the pictures appear. Sodium is in some of those solutions.
Fertilizer
Sodium is a very important element in fertilizers. Farmers use a lot of fertilizer to make sure their crops
grow well. You parents might even use fertilizers in their garden.
Hydrogen
Helium
Carbon
Nitrogen
Oxygon
Sodium
Neon
Magnesium
Iron