TMI the periodic table is telling you
more than you want to know.
Development of the Periodic Table
• Was developed in 1869 by Dmitri Mendeleev
and Lothar Meyer.
• But Mendeleev got credit
because he provide its value.
There are many different ways to
organize the periodic table.
Understand Periodic Trends
• When elements are arranged in increasing
atomic number, we can see repeating patterns in
chemical and physical properties.
• Many of an atoms properties depend on its
electron configuration.
• Also depends on how strongly electrons are
attracted to the nucleus.
Periodic Trends
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Atomic Number & Atomic Mass
Atomic Radii and Ionic Radii
Ionization Energy
Electron Affinity
Electronegativity
Metal, Metalloids & Nonmetals
Groups 1A, 2A, 6A, 7A & 8A
Atomic Number & Atomic Mass
• The number of protons in an atom.
• The mass of an atom.
Atomic Radii
• Result of effective nuclear charge
• Increases top to bottom and right to left
Ionic Radii Trends
• Depends on effective nuclear charge and number
of electrons.
• Cations are smaller then their neutral
counterparts. Anions are large.
• Nuclear charge increases ionic radius decreases.
• Ions with the same charge, increase in size as we
move down the column.
Ionization Energy
• Depends on effective nuclear charge and
electron configuration.
• Increase as we move to left to right and bottom
to top on the periodic table.
Electron Configuration
Electron Affinity
• measure the attraction of an atom to the
electrons.
Electronegativity
• The ability of an atom to attract electron.
Metals
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Shiny luster.
Conduct heat and electricity well.
Malleable and ductile.
Solids at room temp.
High melting temp.
Low ionization energies they often exist as ions.
Where are metals on the periodic table?
Mellatoids
• Have characteristics of metals and nonmetals.
• Where metalloids on the period table?
Nonmetals
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Vary in appearance.
Are poor conductor of heat and electricity.
Low melting temps.
Some exist as diatomic molecule.
Often gain electron due to their
electronegativity.
• Where are nonmetals on the Periodic table?
Group 1A the Alkali Metals
• Soft metallic solids.
• Reactive with waster.
• have a charge of plus one.
Element
Electron
configurati
on
Melting
Point (C)
density
Atomic
Radius (A)
1st
Ionization
Energy
Reactivity
with Water
Lithium
[He]
181
0.53
1.34
520
Least
reactive
Sodium
[Ne]
98
0.97
1.54
496
Potassium
[Ar]
63
0.83
1.96
419
Rubidium
[Kr]
39
1.53
2.11
403
Cesium
[Xe]
28
1.88
2.25
376
Most reactive
Group 2A The Alkaline Earth Metals
• Have typical metallic properties.
• Harder more dense and melt at higher temps.
• Have a +2 charge.
Group 6A The Chalogens
• As you move down in this groups you go from
nonmetal to metalloid.
• Some are gases at room temp some are solids.
• Have a -2 charge.
Group 7A, The Halogens
• Nonmetal diatomic molecules.
• High electronegativity.
• Have a -1 charge.
Group 8A the Noble Gases
• They are inert nonmetal gases.
• Have a complete valence shell of electrons.
• Have no charge.
Effective Nuclear Charge
• How strongly outer electron are attracted to the
nucleus this determine many atomic properties.
• Depends on nuclear charge and distance
between nucleus and electrons