chapter 6 the periodic table. dmitri mendeleev is credited with being the father of the periodic...
TRANSCRIPT
Modern Periodic Table• Today’s Periodic Table is arranged by
the elements’ Atomic Number.• Elements with similar properties are
placed in the same column on the periodic table.
Modern Periodic TablePractice: Find the period and
group of the following elements:
Period Group• Ca _____ _____• Al _____ _____• Zr _____ _____• Xe _____ _____• Ra _____ _____• U _____ _____
Metals• Three or fewer electrons in the outer
energy level• Good conductors of heat and
electricity• Malleable (shapeable)• Metals are hard solids with
shiny surfaces
Nonmetals• Five or more electrons in the outer
energy level• Poor conductors of heat and
electricity• Most are gases or brittle solids• Dull surfaces
PP: Identify the following elements as metals, nonmetals, metalloids:
a) Sulfur (S)b) Hydrogen (H)c) Chromium (Cr)d) Tellurium (Te)
So What’s The Deal With The Shape?
• The distribution of electrons around an atom was used to create the shape of the Periodic Table.
• The radius of positive ions (cation) is smaller than that of the parent atom.
• The radius of negative ions (anion) is larger than that of the parent atom.
+
Atom Ion
-
Atom Ion
Ionic Radii
• PP: Which has the largest ionization energy?– Magnesium (Mg)– Silicon (Si)– Sulfur (S)– Sodium (Na)
Factors Affecting Ionization Energy
A strong nuclear charge will increase ionization energy.
Strong shielding effect will decrease ionization energy.
A full octet will increase ionization energy.
Ionization Energy of sodium, magnesium, and aluminum:
Na 496 4563 6913 9541Mg 737 1450 7731 10545Al577 1,816 2,881 11,600
Explain the discrepancy in ionization energy.
Electronegativity• Electronegativity is the ability
of an atom to attract the electrons from another atom.