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Atomic Theory and Structure The Periodic Table

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Title: Atomic Theory and Structure The Periodic Table


1
Atomic Theory and StructureThe Periodic Table
  • Discovery of the Atoms and their Properties
  • Periodic Table
  • Trends in the Periodic Table
  • Elements and their Names

2
History of the Atom
  • From ancient Greek times of philosophy to today's
    technological era of quantum physics, scientists
    have been mesmerized by what is thought to be the
    smallest particle - the atom. In Greek, the
    prefix "a" means "not" and the word "tomos" means
    cut. Thus, atomos or atom means uncuttable or
    undividable.

3
It all began with
  • All matter is made up of undividable particles
    called atoms.
  • There is a void, which is empty space between
    atoms.
  • Atoms are completely solid.
  • Atoms are homogeneous, with no internal
    structure.
  • Atoms vary in 1)Size 2) Shape 3) Weight

4
September of 1803

Dalton was the first to propose that elements
would be identified by symbols. He also built on
the research of ancient scientists saying
John Dalton, Father of Modern Atomic Theory
5
Daltons Research
  • 1.Chemical elements are made of atoms
  • 2.The atoms of an element are identical in their
    masses.
  • 3. Atoms of different elements have different
    masses.
  • 4. Atoms only combine in small, whole number
    ratios.
  • 5. Atoms can neither be created nor destroyed.

6
J.J. Thompson
  • In 1904 JJ Thomas verified the existence of
    positive particles. He visualized that atoms
    were positively charged pudding and the
    negative matter plums were spread throughout
    the pudding.

The Plum Pudding Model
7
..then came Ernest Rutherford
  • Having worked under JJ Thomas, Rutherford was
    very familiar with the study of the atom.
    Through experiments with radioactive studies he
    proved that atoms had a nucleus. This became
    known as the Gold Foil Experiment due to his use
    of gold foil to reflect the radioactive particles.

8
Neils Bohr
  • Bohr built onto Rutherfords nucleus devising a
    Planetary Model.

9
Pictures of Bohrs Research
The green and red spheres represent the protons
and neutrons of the atom. The orange spheres
represent the electrons.
The charges of the parts in an atom are shown for
a carbon atom.
10
Key Definitions of Todays Atom
  • Proton positive part of the atom found in the
    center of the atom (nucleus)
  • Neutron neutral (no charge) part of the atom
    found in the center of the atom
  • Electron- negative part of the atom found
    circling the center of the atom
  • Nucleus center of the atom home of the proton
    and neutron has the majority of the mass of the
    atom

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11
The Periodic Table
  • The periodic table was organized over the years
    to provide scientists information about the
    different elements. Both man-made and natural,
    the elements are placed in order of things such
    as atomic mass, atomic number, size and other
    things.

12
Dmitrii Mendeleev
  • The first periodic table was put together by
    Mendeleev over 130 years ago. He put the
    elements in order of relationships of reactivity
    (how elements react). His table had holes in it
    that allowed for other elements to be discovered
    at a later time.

13
Todays Periodic Table
  • Mendeleev was correct in his holes on his table.
    Todays table looks very similar to his table.
    It lists the elements in order of their atomic
    number.
  • The first 92 elements have been found in nature.
    All other elements have been man-made.

14
Parts of the Periodic Table
Nonmetals elements possessing the opposite
characteristics of metals. They are often found
in the gaseous state. Examples Hydrogen,
Oxygen, Nitrogen
Metals- elements possessing similar properties
such as metallic luster, reacting well with
elements other than metals, and easily conducts
electricity. Examples Copper, Potassium, Sodium
Transitional Metals- found between metals and
nonmetals often have properties of both. Ex
Silicon, Boron
15
Breaking apart even further
  • Groups of elements vertical columns of elements
    on the periodic table
  • Chemical Family a group of elements that
    includes the number of the column
  • Period of elements horizontal row of elements

16
1 H 1.008
ALKALI
3 Li 6.941
METALS
11 Na 22.99
19 K 39.10
  • Group IA Characteristics
  • The most chemically reactive metals, with the
    exception of Hydrogen, losing their one valence
    electron to non-metals
  • Going down the group, the atomic radius and
    density of the elements increase

37 Rb 85.47
55 Cs 132.9
87 Fr (223)
17
  • Group IIA Characteristics
  • These elements are also very reactive, losing
    their two valence electrons to non-metals

4 Be 9012
12 Mg 24.31
20 Ca 40.08
38 Sr 87.62
Alkaline
56 Ba 137.3
Earth Metals
88 Ra 226
18
Halogens
9 F 18.9984 17 Cl 35.453 35 Br 79.909 53 I 126.904
85 At (210)
  • Group 7A Characteristics
  • These elements all form diatomic molecules.
  • With the exception of At, they all react with
    metals to form salts containing ions with a 1-
    charge.

19
2 He 4.0026 10 Ne 20.179 18 Ar 39.498 36 Kr 83.80
54 Xe 131.30 86 Rn (222)
  • Group 8A Characteristics
  • These elements exist under normal conditions as
    single-atom gases
  • Have little chemical reactivity

Noble Gases
20
Metals
  • Characteristics
  • These have physical properties such as
    conduction of heat and electricity, malleability,
    ductility, and a lustrous appearance
  • They tend to loose electrons to form positive
    ions.

21
Nonmetals
7 N 14.0067 15 P 30.9738 33 As 74.9216
6 C 12.011 14 Si 28.086
5 B 10.811
8 O 15.999 16 S 32.064 34 Se 78.96 52 Te 127.6
  • Characteristics
  • These are found in the upper right-hand corner
    of the table.
  • Lack the physical properties to deem them
    metals.
  • They tend to gain electrons in reactions with
    metals.

22
TRANSITION METALS
30 Zn 65.38
48 Cd 112.4
80 Hg 200.6
112 Uub (277)
Characteristics They show great similarities
within a given period and group The last
electrons are added to the d orbital
23
Lanthanum Series
  • Characteristics
  • Electrons fill the 4f orbital
  • These elements decrease in size, going from left
    to right

24
Actinium Series
  • Characteristics
  • Members of the transitions metals
  • Electrons fill the 5f orbital

25
The Periodic Table
Non-Metals
Noble Gases
Halogens
Alkaline Earth Metals
Alkali Metals
Transition Metals
Metals
Lanthanide Series
Actinide Series
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26
Trends in the Periodic Table
  • When studying the periodic table one can tell
    many things about an element just by its location
    on the table. These trends help scientists
    identify new elements and understand why an
    element has different properties.

27
Atomic Size
  • Atomic size within a group increases as one moves
    vertically down the periodic table.
  • Atomic size within a period decreases as one
    moves horizontally right across the periodic
    table.

28
Ionization Energy(the energy required to remove
an electron from an element)
  • The energy required for elements within a group
    decreases as one moves vertically down the
    periodic table.
  • The energy required for elements within a period
    increases as one moves horizontally right across
    the periodic table.
  • The most metallic elements (Group IA) have the
    lowest energies of any elements on the periodic
    table.

29
Melting Points
  • Melting points of elements increase when one
    moves horizontally right across the periodic
    table until about half way across the periodic
    table. After this point the melting points
    decrease when moving right across the periodic
    table.
  • Carbon has the highest melting point of any
    element (4100 C)

30
Density of Elements
  • Densities within a group increase as one moves
    vertically down the periodic table.
  • Densities within a period first increase then
    decrease when moving horizontally right across
    the periodic table. The switch occurs near Group
    VIIIB.
  • Elements with the greatest densities are at the
    center of Period 6.

31
Gathering Information from the Periodic Table
  • When one looks at a periodic table, there are
    many letters and numbers that help identify the
    elements and give way to their characteristics.
    Understanding these letters and numbers will
    allow for a better understand of each element.

32
Atomic Mass (Mass Number)
1 H 1.01
  • The average of all of the masses of the naturally
    occurring isotopes of an element.
  • The mass number is the rounded atomic mass. It
    is the number of protons and neutrons found in an
    atom.

33
Atomic Number
1 H 1.01
  • The number of protons in the nucleus of an atom

34
Protons, Neutrons, and Electrons
  • of Protons same as the atomic number
  • of Electrons same as the atomic number and the
    number of protons
  • of Neutrons found by subtracting the atomic
    number from the mass number

35
Example
9 F 19.00
9
  • of Protons _______________
  • of Electrons _______________
  • of Neutrons _______________

9
10 (19 9)
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36
Names and Symbols of Elements
  • Looking at the periodic table reveals the symbols
    of each element. These symbols provide an easier
    way to write out each element rather than writing
    the long word each time. The shortcut in writing
    was devised based upon the origin of the
    elements name. Learning the symbols makes
    recording the scientific data easier.

37
Common Elements and Their Symbols
38
Common Elements with Unique Symbols
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