Transcript Periodic Table of Elements

Periodic Table of Elements
Pages 124-167
Ch.4.1, 4.2, 4.3, 4.4 and 5.1
Dmitri Mendeleev
• He recognized patterns in
the element’s approximate
atomic masses and their
ability to bond with other
elements.
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Periodic Table
• Based on atomic masses
and their ability to bond with
other elements, Mendeleev
constructed the first periodic
Table.
The Atom
• Nucleus: The core of the atom
that contains two different
subatomic particles.
The Atom cont…
• Protons: Have a positive charge.
• The number of protons equals the
number of electrons.
The Atom cont…
• Neutrons: Have no
Charge.
The Atom cont…
• Electrons Negative
charge.
• .
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Atomic Numbers, Symbols and
• Atomic
Mass
number is
the smaller
number and
the number
of protons
in the
nucleus.
47
Ag
Element
Symbol
Element
Name
Silver
107.868
Atomic mass is all the protons
and neutrons added together.
How to calculate # of neutrons
• Atomic mass - Atomic number = # of neutrons
This element is
Nitrogen. Its
mass is 14. So
atomic # of 7,
minus atomic
Count the number mass of 14,
of protons. What equals 7
neutrons.
element is it?
How to Calculate Number of
Electrons
• The number of electrons equal the
number of protons.
7
electrons
7
protons
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Isotopes
• When atoms of the same
element have a different
number of neutrons
Valence Electrons
• The electrons on
the outermost ring
or energy level
that can be
shared or
transferred with
other atoms to
make compounds.
Valence Electrons and
Bonding (ch. 5.1 pgs. 176-182)
The number of valence electrons
in an atom of an element
determines many properties of
that element, including the ways
in which the atom can bond with
other atoms.
Take out a piece of
paper, stand up
and stretch
Without any talking, use your notes
and book to answer the following
questions.
• What is inside an atom? (pg. 126-127)
• What information does the periodic table tell
us? (pg. 132-133)
• What are the columns called? What are the
rows called? (pg. 136)
• How do elements relate to each other in
rows? What about columns? (pgs. 136)
Groups –Families
Periods- elements in a
elements period are not alike,
in a
but gradually change as
group
you move from left to
have veryright.
similar characteristics
i.e. bonding, reactivity,
valence electrons
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METALS
•Almost 75% of
all elements are
classified as
metals.
Properties of Metals
• Conductors: Metals are
good at conducting
electricity.
• Malleable: Ability to
bend or pound into
shapes.
Properties of
Metals
•Ductile: Pull or
stretch into wire.
•Many are shiny,
hard and magnetic.
Properties of Metals cont…
• Reactivity: Ability to react
and combine with other
elements. Some are more
reactive than others.
Sodium (Na) and potassium
(K) are some of the most
reactive metals.
Alloys
•Metals can easily
combine into
different mixtures
of elements.
Examples of alloys
• Steel: Fe+C+Cr+V
• Bronze: Sn+Cu
• Brass: Cu+Zn
• White Gold: Ag+Au+Zn+Cu
• Yellow gold: Au+Cu+Ni+Zn
ALKALI METALS-Group 1
•So reactive that they
are never found
isolated in nature,
only combined with
other elements.
ALKALI METALS-Group 1
Characteristics Properties:
• Soft
• Shiny
• One valance: electron makes them
very reactive.
Write down the following:
Reactivity of Hydrogen demo
• Purpose: To isolate and observe the
reactivity of an alkali element: H
(hydrogen).
• Materials: 250mL flask, mossy zinc,
hydrochloric acid, balloon, string,
funnel, meter stick, and matches.
• Place enough zinc into the flask to cover the
bottom.
• Place the funnel on the mouth of the flask.
• Pour enough HCL into the flask to cover the
zinc (about 2cm high)
• Quickly, but carefully remove the funnel and
place the balloon over he mouth of the flask.
• Let the gas fill the balloon.
• Tie the string around the balloon and remove
the balloon from the flask.
• Tie the balloon to a safe place.
• Attach a match to the end of a meter stick and
light the balloon with the lit match.
Alkaline Earth Metals
• Group 2 metals.
• Very reactive, not as
reactive as alkali metals due
to having one more valence
electron.
• Ca: important for bones.
TRANSITION METALS
• All are good conductors of
electricity.
• Fairly stable.
• Fe : Iron is important for
carrying oxygen in your
blood.
Lanthinides and Actinides
• AKA Rare Earth Elements.
• Placed at the bottom of the
table for convenience.
• They are in Periods 6 and 7.
Metalloids
Have some properties of both
metals and nonmetals.
They are located on the
zigzag line between the
metals and the nonmetals.
Physical Properties:
•Can be good at conducting electricity, therefore
some are used as computer chips such as Si
and Ge.
•Non metals lack properties of
metals.
•They are on the right side of the
periodic table.
Fe
Non-metals
O
Fe2O3 = Iron Oxide = Rust
•Non metals usually react with metals to make
compounds.
•In general, metals give up electrons to nonmetals.
Predicting Reactions
• Elements become more stable as they
gain more valence electrons.
• As a result, atoms will gain, lose or share
electrons to form compounds so that they
have 8 valence electrons or a full shell.
• This is called the Octet Rule. However
there are many exceptions, but this is an
easy way to predict common reactions.
Atoms are “happy” when they have either
only 2 valence electrons (He and H) or 8
electrons.
Families of Non-metals
• Carbon Family is
group 14 and is the
only non-metal in
that group and is
found in all living
things.
Carbon
needs 4e
Oxygen
needs 2e
2 O on 1
C
makes…
CO2
Families of Non-metals
Nitrogen Family is
group 15 and
Nitrogen makes up
78% of the earth’s
atmosphere.
Nitrogen
needs 3e
Hydrogen
can give
1e
3 H on 1
N
makes…
NH3
Families of Non-metals
Oxygen family is
group 16 and
oxygen makes up
approximately 20%
of the earth’s
atmosphere.
Oxygen
needs 2e
Magnesium
can give 2e
1 Mg on
1O
makes…
MgO
Families of Non-metals
• The Halogen family
is group 17. Each
element has 7
electrons, therefore it
commonly takes one
electron away from
group one metals to
make compounds.
Chlorine
needs 1e
Potassium
can give
1e
1 K on 1
Cl
makes…
KCl
Families of Non-metals
• The Noble Gases are
group 18. They have 8
valence electrons,
therefore they are very
stable and nonreactive.
Hydrogen
• Not a part of
group 1.
• Generally
found as H2
•It doesn’t fit into any other family
because it is so different from all other
elements.
The Sun and Nuclear Fusion
• How does the sun produce energy?
• During nuclear fusion, two atomic nuclei
collide and fuse.
Chemical compositions of
Stars:
Each element absorbs
different wavelengths of
light and shows up as lines
on a spectrum.
Temperature: Stars
at different
temperatures
produce different
line spectra.
Star Spectrums
• Astronomers can use line spectrums to
identify the chemical elements in a star.
Each element produces a characteristic
pattern of spectral lines.
The Hertzsprung-Russell
Diagram
• Astronomers use H-R diagrams to
classify stars and to understand how
stars change over time.
The Earth’s Seasons
• Equinox: Two days of the year half
way between the solstice, the earth’s
axis is neither pointed away or
toward the sun. The daylight hours
are equal to the nighttime hours.
• Vernal Equinox: or Spring equinox is
on March 21st
• Autumnal Equinox: is September
23rd.