THE PERIODIC TABLE

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THE PERIODIC TABLE

• is arranged in order of increasing number of
  protons.
• the atomic number of an element is the number of
  protons in the nucleus and the number of
  electrons in a neutral atom.
• the atomic weight increases with increasing
  number of protons and neutrons.
• the atomic weight is the average weight of all
  the isotopes of that element (the average of the
  natural abundance x mass number).

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THE PERIODIC TABLE

• is divided into metals (left side), nonmetals
  (right side), and metalliods.
• is arranged in rows (across) in order of
  increasing energy levels of valence electrons
  (called periods). The period number represents
  the energy level for that row.
• is arranged in columns (down) in order of similar
  orbitals for the valence electrons (called
  groups).
• The elements are represented by one or two letter
  symbols, which have some correlation to the
  element name.

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THE PERIODIC TABLE

• Metals
• Located on the left side of the periodic table
• Tends to lose electrons to form cations
• Has low ionization energies electronegativity
  values
• Forms compounds with nonmetals but not other
  metals
• Good conduction of heat and electricity
• Lustrous malleable solids excepts Hg which is
  a liquid
• Ductile

• Nonmetals
• Located on the right side of the periodic table
• Tends to gain electrons to form anions
• Has high ionization energies electronegativity
  values
• Forms compounds with both metals and nonmetals
• Poor conduction of heat and electricity
• Non-lustrous brittle or gaseous
• Non-ductile

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THE PERIODIC TABLE

• is divided into "blocks" which represent the
  orbital the electron occupies s, p, d, and
  f.
• is read left to right 1s, 2s, 2p, 3s, 3p,
  4s....
• is arranged as representative elements (s and p
  block elements), transition metals (d block
  metals), lanthanides and actinides (f block
  metals).
• is arranged in order of increasing energy of the
  subshells the lowest energy level is always
  filled first.
• the noble gases are unreactive since they have a
  completely filled shell and are the lowest in
  energy.

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THE PERIODIC TABLE

• Groups or families display similar physical and
  chemical reactivity.
• the group number (roman numerals) on top
  represents the number of valence electrons
  available for that column.
• common groups are
• group I alkali metals
• group II alkaline earth metals
• group VI chalogens
• group VII halogens
• group VIII noble or inert gases

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THE PERIODIC TABLE

• demonstrates the trends in atomic properties the
  periodicity of the elements.
• Atomic radius,
• ionization energy,
• electronegativity,
• magnetism
• are some of the properties of atoms which can
  be predicted using the periodic table.

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THE PERIODIC TABLE

• Atomic radius
• In general, the atomic radii of the elements
  within a row (period) decreases from left to
  right due to an increase in nuclear charge
  whereas the radii increases down a column (group)
  due to the addition of electrons in higher energy
  levels.

decreases
increases
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THE PERIODIC TABLE

• Ionization energy
• This energy is required to remove an electron
  from an atom in the gaseous state. The first
  ionization energy is the amount of energy
  required to remove the first electron from an
  atom as demonstrated below
• M(g) ? M(g) e-

increases
The first ionization energy generally increases
across a period and decreases down a group.
decreases
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THE PERIODIC TABLE

• Electronegativity
• Electronegativity describes the ability of an
  atom to attract electrons to itself in a chemical
  bond. It is the attractive force that one atom
  has for a shared pair of electrons of a different
  atom in a covalent bond. Notice that the
  electronegativity can be related to the
  ionization energy and electron affinity.

increases
The electro-negativity generally increases across
a period and decreases down a group.
decrease
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THE PERIODIC TABLE

• Magnetism
• A Paramagnetic atom is attracted to a magnetic
  field because it has one or more unpaired
  electrons.
• A Diamagnetic atom is not attracted to (weakly
  repelled from) a magnetic field because all of
  the electrons are paired up.

Paramagnetic Li ________ 2s _________
1s Diamagnetic He _________ 1s
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PRACTICE PROBLEMS about the PERIODIC TABLE
Classify the elements as representative,
transition, lanthanide, or actinide. 1.
Cd 2. Te 3. Sr 4. Al 5.Gd 6. Rh 7. Cf 8.
Be 9. Pd 10. O Classify the elements by the
group name 1. Be 2. Rb 3. Xe 4. Se 5.
Br Arrange in order of increasing
electronegativity. C O Be N Sr S
B Arrange in order of increasing first
ionization energy. C O Be N Sr S
B Arrange in order of increasing atomic
radius. C O Be N Sr S B
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ANSWERS
Classify the elements as representative,
transition, lanthanide, or actinide. 1.
Transition 2. Representative 3. representative
4. representative 5. lanthanide 6.
transition 7. actinide 8. representative
9. transition 10. Representative Classify
the elements by the group name 1. Alkaline
earth 2. alkali 3. noble 4. chalogen 5.
halogen Arrange in order of increasing
electronegativity. Sr lt Be lt B lt S
C lt N lt O Arrange in order of increasing
first ionization energy. Sr lt Be lt B lt S
C lt N lt O Arrange in order of increasing
atomic radius. O lt N lt C lt S lt
B lt Be lt Sr
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GROUP STUDY PROBLEMS
Classify the elements as representative,
transition, lanthanide, or actinide. 1.
Ca 2. Tb 3. Hg 4. Es 5.Pb Classify the
elements by the group name 1. Kr 2. I 3.
Mg 4. Na 5. O Arrange in order of increasing
electronegativity, first ionization energy,
atomic radius. Si F In Al Ba Classify as
metal, nonmetal, or metalliod 1. Kr 2.
I 3. Mg 4. Na 5. O Classify as paramagnetic
or diamagnetic 1. Kr 2. I 3. Mg 4.
Na 5. O