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The Periodic Table and Periodic Law - Coggle Diagram
The Periodic Table and Periodic Law
Lesson 6.3
Leen Mrad 9B
Atomic Radius
Atomic size is a
periodic trend influenced by electron configuration; how closely an atom lies to a neighboring atom
Metals
: Atomic radius is half the distance between adjacent nuclei in a crystal of the element
Molecules
: Atomic radius is half the distance between nuclei of identical atoms.
Trend
: Atomic Radii decrease from left to right across a period, and increase down a group
Due to: Increasing positive charge in nucleus, principal energy within period remains the same, and valence electrons are not shielded from increasing nuclear charge.
Electronegativity
Indication of ability to attract electrons in a chemical bond
Trend:
Decreases down a group, and increases left to right across a period.
Halogen has the greatest electronegativity.
Noble Gases do not have electronegativity values
Ionic Radius
When atoms gain electrons, they can become larger; the addition of an electron increases electrostatic repulsion
Trend
: Ionic radii of positive ions decrease from left to right, whereas ionic radii of negative ions decrease from left to right beginning with group 15/16. Both positive and negative ions increase downwards.
A
negative
ion is
larger
than its atom. A
positive
ion is
smaller
than its atom.
Ionization Energy
The energy required to remove an electron from a gaseous atom.
The energy required to remove the
first
electron is called the
first
ionization energy.
Atoms with low ionization energy values are likely to form positive ions.
Atoms with high ionization energy are likely to form negative ions
Each successive ionization requires more energy, but it is not a steady increase.
The increase in ionization energy shows that atoms hold onto their inner core electrons stronger than they hold onto their valence electrons.
Trend:
Ionization energy increases from left to right across a period, and decreases down a group