Download Periodic Table2011

chlorine
silver
nitrogen
gold
oxygen
hydrogen
helium
mercury
sodium
niobium
neodymium
carbon
Physical & Chemical Properties
What are properties?
• Matter has observable and measurable
qualities.
• We can use general properties to identify
substances.
• Two basic types of properties of matter:
Physical properties and Chemical
properties:
Physical Properties
• Physical properties are used to identify,
describe and classify matter.
– Characteristic of a substance that can be
observed (using your senses) without
changing the substance into something
else.
Hardness
Texture
Color
Odor
Taste
Not Chemicals
Temperature
More EXAMPLES - Physical
• size, shape, freezing point, boiling
point, melting point, magnetism,
viscosity, density, luster and many
more.
– Viscosity - The resistance of a liquid to
flowing.
– Examples:
– Low viscosity-water, rubbing alcohol
– High viscosity-honey
Chemical Properties
• Chemical properties are characteristics
involved when a substance interacts
with another substance to change its
chemical make-up.
Flammability
Rusting
Color change
Creating a
Reactivity with
new chemical
water
product
Creating gas
bubbles
pH
The material itself is the same before and
after the change. The change CAN be
“undone.”
•Ice melting: an example of physical change
Chemical Change
Occurs when one or more substances are changed into
entirely NEW substances
They have different properties from the original substance
•Some signs (or evidence) of chemical change are:
•a gas is produced,
•the temperature changes,
•a substance disappears,
•a solid is formed
•a color change occurs,
•a new odor is produced.
Chemical Change
•Cannot easily be undone
•Have you ever tried to un-fry and egg?
Heat is added
Original Substance-Eggs
New Substance-Fried Eggs
Examples of Physical and Chemical Changes
Physical Changes
Chemical Changes
Rubbing alcohol
evaporates on your hand.
Hydrogen peroxide
bubbles in a cut.
A juice box in the freezer
freezes.
Gasoline is ignited.
Water evaporates from
the surface of the
ocean.
Butter melts on warm
toast.
Rust forms on a nail left
outside.
Clay is molded into a new
shape.
Bread becomes toast.
Milk goes sour.
Summing it Up
Physical Change:
The matter is the same.
The original matter can be recovered.
The particles of the substance are
rearranged.
Chemical Change:
 The matter is different.
The old matter is no longer present.
The original matter cannot be recovered.
Copper Penny Story
Physical & chemical properties are very important when it comes to
making coins.
Cost is also important.
• In the 1980s copper became to expensive to use for penny
production in the USA.
• A replace with similar properties was needed.
• Zinc was used to replace most of the copper in all post 1982 pennies.
• Zinc is as hard as copper, has similar density, its readily available and
less expensive than copper.
• Zinc is more reactive and in the 1940s was used to make pennies
and it corroded so production ended.
• Post 1982 pennies are copper on the outside and zinc on the inside.
Periodic Table
Periodic Table
• The modern table was
devised in 1869 by Dimitri
Mendeleev
• He arranged the elements by
weight and by their chemical
properties
Mendeleev first trained
as a teacher in the
Pedagogic Institute of
St. Petersburg before
earning an advanced
degree in chemistry in
1856.
"...if all the elements be arranged in order
of their atomic weights a periodic repetition
of properties is obtained." - Mendeleyev
Concerning the relation between the properties and atomic
weights of elements. By D. Mendeleev.
•Arranging the elements in vertical columns with increasing
atomic weights, so that the horizontal rows contain similar
elements, again in increasing weight order, the following table is
obtained from which general predictions can be drawn
•Elements show a periodicity of properties if listed in order of
size of atomic weights.
•Elements with similar properties either have atomic weights
that are about the same (Pt, Ir, Os) or increase regularly (K, Rb,
Cs).
•The arrangement of the elements corresponds to their valency,
and somewhat according to their chemical properties (eg Li, Be,
B, C, N, O, F).
Concerning the relation between the properties and atomic weights of
elements. By D. Mendeleev.
•The commonest elements have small atomic weights.
•The value of the atomic weight determines the character of
the element.
•There are unknown elements to discover eg elements
similar to Al and Si with atomic weights in range 65-75.
•The atomic weights of some elements may be changed
from knowing the properties of neighbouring elements. Thus
the atomic weight of Te must be in range 123-126. It cannot
be 128.
•Some typical properties of an element can be predicted
from its atomic weight.
Periods and Groups
• Horizontal rows in the periodic table are
called periods
• Vertical columns are called groups
• We will learn later why the elements can
be arranged in this fashion based on the
arrangements of the electrons outside the
nucleus
Periods and Groups
• Sizes of the atoms decrease as we move from left to right across a
period
• This is due to the increasing number of protons in the nucleus, so
the electrical attraction between the nucleus and the orbiting
electrons gets stronger and pulls the electrons closer to the nucleus.
Periods and Groups
• We can display the table to demonstrate other properties
as well
• As you move from left to right across a period, the ability
of the atom to attract another electron increases
• This property is called electronegativity
Key to the Periodic Table
• 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.
– For instance, hydrogen
has 1 proton, so it’s
atomic number is 1.
– The atomic number is
unique to that element.
No two elements have the
same atomic number.
• Atomic Mass (bottom number) refers to the
“weight” of the atom.
• It is derived at by adding the number of protons
with the number of neutrons.
Atomic Mass and Isotopes
• While most atoms have
the same number of
protons and neutrons,
some don’t.
• Some atoms have
more or less neutrons
than protons. These
are called isotopes.
Symbols
C
Carbon
Cu
Copper
• All elements have
their own unique
symbol.
• It can consist of a
single capital letter,
or a capital letter
and one or two
lower case letters.
Properties of Metals
• 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
• 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.
Sulfur
Properties of Metalloids
• 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.
Silicon
Hydrogen
• The hydrogen square sits atop the Alkali
Metals Family, but it is not a member of that
family. Hydrogen is in a class of its own.
• It’s a gas at room temperature.
• It has one proton and one electron in its one
and only energy level.
• Hydrogen only needs 2 electrons to fill up its
valence shell (outer most electron shell).
Alkali Metals
• They are the most
reactive metals.
• They react violently
with water.
• Alkali metals are
never found as free
elements in nature.
They are always
bonded with
another element.
What does it mean to be
reactive?
• We will be describing elements according to their
reactivity.
• Elements that are reactive bond easily with other
elements to make compounds.
• Some elements are only found in nature bonded with
other elements.
• What makes an element reactive?
– An incomplete valence electron level.
– All atoms (except hydrogen) want to have 8 electrons in their
very outermost energy level (This is called the rule of octet.)
– Atoms bond until this level is complete. Atoms with few valence
electrons lose them during bonding. Atoms with 6, 7, or 8
valence electrons gain electrons during bonding.
Alkaline Earth Metals
• They are never found uncombined in nature.
• They have two valence electrons.
• Alkaline earth metals include magnesium and
calcium, among others.
Transition Metals
• These are the metals you are probably most familiar: copper,
tin, zinc, iron, nickel, gold, and silver.
• They are good conductors of heat and electricity.
• The compounds of transition metals are usually brightly colored
and are often used to color paints.
• Transition elements have 1 or 2 valence electrons, which they
lose when they form bonds with other atoms.
Boron Family
• The Boron Family is named
after the first element in the
family.
• Atoms in this family have 3
valence electrons.
• This family includes a
metalloid (boron), and the
rest are metals.
• This family includes the
most abundant metal in the
earth’s crust (aluminum).
• Atoms of this family have 4
valence electrons.
• This family includes a nonmetal (carbon), metalloids,
and metals.
• The element carbon is
called the “basis of life.”
There is an entire branch
of chemistry devoted to
carbon compounds called
organic chemistry.
Nitrogen Family
• The nitrogen family is named
after the element that makes
up 78% of our atmosphere.
• This family includes nonmetals, metalloids, and
metals.
• Atoms in the nitrogen family
have 5 valence electrons.
They tend to share electrons
when they bond.
• Other elements in this family
are phosphorus, arsenic,
antimony, and bismuth.
Chalcogen Family
• Atoms of this family have 6
valence electrons.
• Most elements in this family
share electrons when
forming compounds.
• Oxygen is the most
abundant element in the
earth’s crust. It is extremely
active and combines with
almost all elements.
Halogen Family
• The elements in this
family are fluorine,
chlorine, bromine, iodine,
and astatine.
• Halogens have 7 valence
electrons, which explains
why they are the most
active non-metals. They
are never found free in
nature.
Halogen atoms only need to gain 1
electron to fill their outermost energy
level.
They react with alkali metals to form
salts.
Noble Gases
• Noble Gases are colorless gases that are extremely unreactive.
• One important property of the noble gases is their inactivity.
They are inactive because their outermost energy level is full.
• Because they do not readily combine with other elements to
form compounds, the noble gases are called inert.
• The family of noble gases includes helium, neon, argon,
krypton, xenon, and radon.
• All the noble gases are found in small amounts in the earth's
atmosphere.
Rare Earth Elements
• The thirty rare earth
elements are composed
of the lanthanide and
actinide series.
• One element of the
lanthanide series and
most of the elements in
the actinide series are
called trans-uranium,
which means synthetic or
man-made.