periodicity. atomic radius ionic radius ionization energy electron affinity electronegativity...
TRANSCRIPT
Periodicity
Periodicity
• Atomic radius• Ionic radius• Ionization energy• Electron affinity• Electronegativity• Metallic character
Atomic radius• (Size) One half the distance between the nuclei of
identical atoms that are bonded together.Period• Decreases across a period• Atoms shrink across a period because added protons
in the nucleus pull the added electrons more tightlyGroup• Increases down a group• Atoms get bigger as you go down the group/ family
because orbitals are added to make room for more electrons
Atomic radius
Ionic Radius
• The trend is the same as atomic radius– size increases down a group and decreases across a period
Ionization Energy• Amount of energy required to remove an electron
from an atom.Period• Increases across a period • The outer-most electron becomes more difficult to remove
across a period since added protons exert a stronger attraction.
Group• Decreases down a group• The outer-most electron is easier to remove as you move
down a column since each time you are one energy level farther from the nucleus
Ionization energy
Electron Affinity• The amount of energy released when an
atom takes on an electron.
Period• Increases across a period
Group• Increases down a group
Electron affinity
Electronegativity• The tendency of a bonded atom to attract the electrons in
that bond.• Period• Increases across a period• The pull of the increased protons in the nucleus is enough to
attract electrons that come close to the outer limits of the atom from other sources.
• Group• Decreases down a group• Electrons are more difficult to hold onto as you move down
a column.
Electronegativity
Metallic characterPeriod•Decreases across a period •Metallic properties are most pronounced at the left side of the table where shielding is at a maximum.
Group•Increases down a group•Properties will also increase as you move down a family since shielding improves.
Metallic character
• Fr (Francium) is the most reactive metal.• F (Fluorine) is the most reactive non-metal.• The noble gases are very un-reactive.