Periodic Table

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Transcript Periodic Table

1790’s French chemist Antoine-Laurent Lavoisier
made the first periodic table.
1803- John Dalton
improved the periodic
table by assigning
symbols and masses
to each element.
1869- Dimitri Mendeleev, a Russian
chemist, arranged the 63 known
element at the time, into groups
based on their chemical
properties and atomic weights.
1912- Henry Moseley, an English
physicist improved Mendeleev’s
table by listing the elements by their
atomic number.
1940’s- Glenn Seaborg discovered
plutonium and all the transuaranic
elements from 94 to 102. He was
awarded the Nobel Prize in chemistry
for his work in 1951. Element 106
has been named seaborgium (Sg) in
his honor.
Today’s periodic table:
arranged by atomic number
groups-columns of elements having similar chemical properties
periods-in order of atomic number, increase across the period or row
Periodic Table
Periodic Law
When elements on the periodic table are arranged by atomic number,
relationships and similarities in properties can be seen.
This means that when the elements from the periodic table are arranged in
a certain way from lowest to highest atomic number (the number of
protons), the ones near each other will have similar properties!
The_Periodic_Table.asf
What do elements in the same group have in
common?
They have the same number of valence electrons and other similar
chemical and physical properties.
They all have the same number of electrons in the outer shell and
thus react similarly.
For example, all the group 1 (Alkali metals) elements react
violently with water.
From left to right in a period, explain how the
atoms change.
Each row or period of the periodic table corresponds to the number
of electron shells in an atom of the elements in that row.
The elements in the second period each have two electron shells,
and the elements in the sixth period have six electron shells.
Rough draft reports due tomorrow...............
The Periodic Table
I. History
A. Lavoisier, Dalton
B. Mendeleev, Meyer
C. Rutherford, Moseley
D. Seaborg
II Organization
A. Periods
B. Groups
C. Group names and info
III. Metals, Nonmetals, Metalloids
Text pages
98 - 103
Read handout
on line.....
IV. New Elements
A. Identifying
B. Naming the new elements
CALCULATORS NEEDED IN CLASS
FOR WEDNESDAY!
BE SURE AND BRING YOUR OWN!
Elements
fall into three groups
characterized by similar properties.
metals, nonmetals, and metalloids
METALS:
majority of elements…where on the periodic table???
Shiny luster
Good conductors of heat and electricity
Solid at room temperature
Malleable, or can be shaped
Ductile, or can be drawn into wires without breaking
3/4 of all elements are metals
Most metals have one, two or
three electrons in their outer shell
During chemical reactions, metal atoms lose their outer electrons to other atoms,
usually, non metals.
The outer electrons are far from the positive pull of the protons, thus held loosely in
place.
A metal atom becomes stable, or nonreactive, when it has lost its outer electron.
NONMETALS
how many elements and where on the periodic table???
Dull in appearance
Poor conductors of heat and electricity
Many are gases at room temperature
Brittle, cannot change shape without breaking
96% of the human body is made up of nonmetals
METALLOIDS:
how many elements and where on the periodic table???
Have characteristics of both metals and nonmetals
Do not conduct heat and electricity as well as metals
All are solids at room temperature
Group Information on the Periodic Table
The periodic table groups are as follows
(in the brackets are shown the old systems: European and American):
Group 1 (IA,IA): the Alkali metals
Group 2 (IIA,IIA): the Alkaline earth metals
Group 3 (IIIA,IIIB)
Group 4 (IVA,IVAB)
Group 5
Group 6
Group 7
Group 8
Group 9
Group 10
Group 11
Group 12 (IIB,IIB)
Group 13 (IIIB,IIIA): the Boron Group
Group 14 (IVB,IVA): the Carbon Group
Group 15 (VB,VA): Nitrogen Group
Group 16 (VIB,VIA): the Chalcogens
Group 17 (VIIB,VIIA): the Halogens
Group 18 (Group 0): the Noble gases
Group 1: The alkali metals are lithium, sodium, potassium, rubidium, cesium, and
francium. Hydrogen is also part of this group, but is only in a metal state at great
depths within Jupiter, the pressure is so great that the hydrogen atoms are broken
up and the electrons are freed so that the resulting atoms consist of bare protons.
This produces a state in which the hydrogen becomes metallic.
Alkali Metal Properties
Lower densities than other metals
One loosely bound valence electron
Largest atomic radii in their periods
Low ionization energies
Low electronegativities
Group 2: The alkaline earth metals
All the elements are all metals with a shiny, silvery- white color.
They are all soft, low density metals, which react readily with
halgens to form ionic salts, and with water but not as rapidly as
the alkaline metals. For example, sodium and potassium react
with room temperature water, however, magnesium reacts only
with steam and calcium reacts only with hot water.
The elements have two electrons in their valance, or outermost
shell.
38 elements in groups 3 through 12 of the
periodic table are called "transition
metals". As with all metals, the transition
elements are both ductile and malleable,
and conduct electricity and heat. The
interesting thing about transition metals is
that their valence electrons, or the
electrons they use to combine with other
elements, are present in more than one
shell. This is the reason why they often
exhibit several common oxidation states.
There are three noteworthy elements in
the transition metals family. These
elements are iron, cobalt, and nickel, and
they are the only elements known to
produce a magnetic field.
The Boron Group, Group 13
Except for boron itself, which is a nonmetal, the elements of
group IIIA, or Group 13, are metals (aluminum, gallium,
indium, thallium). Even boron in its elemental state is a hard
gray material that might be mistaken for a metal.
The elements of group IIIA have a valence (number of
bonds to atoms other elements) of three. There are
exceptions. Thallium often has a valence of 1 as well as of
3. Boron often has a valence of 4 (bonds) because of filling
the empty space in its octet from other species from
outside.
As a group, the elements of the boron group decrease in
electronegativity as one goes down the column.
Group 14: The Carbon Group has the elements change from nonmetallic in character at the top of the Group to metallic at the
bottom.
Carbon is a non-metal, silicon and germanium are metalloids, and
tin and lead are typical metals. The general reactivity of the
Group as a whole is therefore difficult to ascertain, and the
reactivity of each element must be considered individually.
Diamond has a very high refractive index (the reason for its sparkle) and
this, along with its rarity, has made it valuable as a jewel. However, it is
also the hardest natural substance known and so is important
industrially.
The most important physical property of silicon is that it is a semiconductor. Small silicon chips, just a few millimetres square, have
revolutionised the computer and microprocessor industries.
Tin and lead, as typical metals, are good conductors of electricity.
Group 15: Nitrogen Group includes nitrogen, phosphorus,
arsenic, antimony and bismuth and ununpentium.
The name pnictogens is also sometimes used for this group; it is not
approved by IUPAC . The spelling pnicogen is also recorded. Both
spellings derive from the Greek πνίγειν (pnigein), to choke or stifle,
which is a property of nitrogen.
The chalcogens are the name for the periodic table group
16. It consists of the elements oxygen (O), sulfur (S),
selenium (Se), tellurium (Te), the radioactive polonium
(Po), and the synthetic ununhexium (Uuh).
Oxygen and sulfur are nonmetals, polonium is a true
metal, and selenium and tellurium are metalloid
semiconductors Nevertheless, tellurium, as well as
selenium, is often referred to as a metal when in
elemental form.
Chalcogenides are quite common as minerals. For
example, FeS2 ( pyrite ). The mineral pyrite or iron pyrite
is iron disulfide, FeS. It has isometric crystals that
usually appear as cubes or pyritohedrons. It has a
slightly uneven and conchoidal fracture, a hardness of
6-6. 5, and a specific gravity of 4. Its metallic luster and)
is an iron ore and AuTe2 gave its name to the gold rush
town of Telluride, Colorado
Group 17: the halogens are a chemical series including:
fluorine , chlorine, bromine, iodine, and astatine. The word
comes from Greek roots meaning "salt" and "creator".
These elements are diatomic molecules in their natural
form. They require one more electron to fill their outer
electron shells , and so have a tendency to form a singlycharged negative ion. This negative ion is referred to as a
halide ion; salts For other meanings of the word salt see salt
(disambiguation In chemistry, a salt is a composed of
positively charged cations and negatively charged anions, so
that the product is neutral and without a net charge. They
are typically the product of a chemical containing these ions
are known as halides. A halide is a binary compound, of
which one part is a halogen atom and the other part is an
element or radical that is less electronegative than the
halogen. Most salts are halides.
Group 18: the noble gases are a chemical series which include the
elements helium , neon , argon , krypton , xenon and radon
.
The term noble gas comes from the fact that, just like the common
view of human nobility, these gases generally sit around not doing
anything, and avoid reacting with 'common' elements. The noble
gases were previously referred to as inert gases, but this term is
not strictly accurate now that some have been shown to take part
in chemical reactions.
Because of their unreactivity, the noble gases were not discovered
until the existence of helium was hypothetically deduced from a
spectrographic analysis of the sun, and later on proven when
William Ramsay isolated it.
The noble gases also have very weak inter-atomic forces of
attraction, and consequently very low melting point.
For the Periodic Table:
1. A copy of the Periodic Table with a key to describe
what information is given.
2. Color code the Table as to solids, liquids, gases
3. Label periods and groups
4. Include a report on how the Periodic table came to
be....include all the people who were responsible for
it’s creation.
Use your textbook, encyclopedia, or other sources.
FINAL draft reports due tomorrow...............
The Periodic Table
I. History
A. Lavoisier, Dalton
B. Mendeleev, Meyer
C. Rutherford, Moseley
D. Seaborg
II Organization
A. Periods
B. Groups
C. Group names and info
III. Metals, Nonmetals, Metalloids
IV. New Elements
A. Identifying
B. Naming the new elements
Have you ever wondered what rhyme or reason there is for the placement of
elements in the Periodic Table of the Elements? Believe it or not, this strange
arrangement of elements and data makes perfect sense (if we know what to
look for).
In this activity, we will again practice identifying the numbers of protons,
neutrons, and electrons in the atoms of various elements. We will also make
sketches of atoms using Neils Bohr’s atomic model. Finally, we will arrange
these atom drawings into the first three periods (or rows) of the Periodic Table
of the Elements. By the end of this long process, we should be able to safely
state that the organization of the Periodic Table of the Elements does, indeed,
make sense.
Part A:
Use the table below to help organize all of the key data for the first 18 elements of the
Periodic Table of the Elements.
Atomi Element
Name
c
Numb
er
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Elemen Number
t
of
Symb
Protons
ol
Number Numbe Mass
of
Number
r of
Electro
Neutr
ns
ons
Part B:
Once Part A is finished, we will now make correct Bohr model drawings of
atoms of each of these 18 elements on the sectioned off sheets of paper
provided. Using compasses or other available circle drawing tools, make
these sketches neatly and be sure to include the NAME and SYMBOL of each
element in addition to the details in the model. See the example below.
Part C - checklist of finishing touches:
Cut out all 18 of the atom drawings and lay them out on the large sheet of paper in the
order they are placed in the Periodic Table.
PLEASE, DO NOT GLUE ANYTHING IN PLACE until checked.
Have your seat mate check your project before you glue.
Glue the atom drawings to your Periodic Table of the Elements.
Color-code the electron energy levels. The first (innermost) level will be one color, the
second level another color, and the third level a third color.
Circle ONLY the OUTER electrons in each atom.
Number GROUPS going across the top.
Number PERIODS going down the side.
Give it a neat and appropriate title.
___ Answer all ANALYSIS PROBLEMS on the sheet provided.
Please respond to the following problems completely in the spaces provided below them.
Explain what similarity each of the atoms in a particular group share. Look carefully at your
Periodic Table of the Elements and look for a pattern in the structures of these elemental
atoms.
NOTE: Atoms prefer to be in a state that is stable; in other words ,with a full outer energy
level. They seek to do so by either GAINING electrons to fill a nearly full outer energy level
or by LOSING electrons to empty out a nearly empty energy level.
2a. Using the information above, explain why it is that sodium (Na) so easily bonds (or
reacts) with chlorine (Cl).
2b. Do you think that lithium (Li) would want to bond with chlorine (Cl)?
Explain.
2c. The elements in Group 18 are referred to as noble or inert gases. They are particularly
special because they do not like to react with other elements. Explain why it is that these
elements are so non-reactive.
3. Explain what similarity each of the atoms in a particular period share. Look carefully at your
Periodic Table of the Elements and look for a pattern in the structures of these elemental
atoms.
4. Using what has been learned in this assignment, answer these 3 questions about the
element in Period 4, Group 2:
a. How many outer electrons does each atom have?
b. How many energy levels does it have?
c. Name an element that would behave in a similar way.
5. In the space below, make a Bohr model drawing of the element with atomic number 19.
Next to your drawing, be sure to include the atomic number, name, symbol, and mass numbe
of the element.
6. Name one atom (element) that the atom you drew in problem 5 would likely react with.
Explain why the atom you drew in problem 5 would choose this particular element with which
to react. Use drawings if that would help your explanation.
7. THINK HARD! Magnesium chloride (MgCl2) is a compound that is formed by the reaction
of one magnesium (Mg) atom with two chlorine (Cl) atoms. Using what you have learned in
this project, explain why these atoms would want to combine to form one compound. Use
drawings to help explain your thinking.
5. In the space below, make a Bohr model drawing of the element with atomic number 19. Next to your
drawing, be sure to include the atomic number, name, symbol, and mass number of the element.number 19
Next to your drawing, be sure to include the atomic number, name, symbol, and mass number of the
element.
6. Name one atom (element) that the atom you drew in problem 5 would likely react with. Explain why the
atom you drew in problem 5 would choose this particular element with which to react. Use drawings if
that would help your explanation.
7. THINK HARD! Magnesium chloride (MgCl2) is a compound that is formed by the reaction of one
magnesium (Mg) atom with two chlorine (Cl) atoms. Using what you have learned in this project, explain
why these atoms would want to combine to form one compound. Use drawings to help explain your
thinking.
Attachments
The_Periodic_Table.asf