Atomic Structure :  Metals, Nonmetals, and Semimetals
Metals

Common characteristics:

  • Metallic luster (shine)
  • Generally solids at room temperature
  • Malleable
  • Ductile
  • Conduct heat and electricity
  • Exist as extended planes of atoms
  • Combine with other metals to form alloys which have metallic characteristics
  • Form positive ions, e.g.  Na+, Mg2+, and Al3+
  • Nonmetals

    Common characteristics:

  • Rarely have metallic luster (shine)
  • Generally gases at room temperature
  • Neither malleable nor ductile
  • Poor conductors of heat and electricity
  • Usually exist as molecules in thier elemental form
  • Combine with other nonmetals to form covalent
  • Generally form negative ions, e.g.  Cl-, SO42-, and N3-
  • The differences in the characteristics of metals and nonmetals can be explained by the following:
  • Metals have relatively few electrons in their valence shells.
  • Metals have lower ionization energies than nonmetals.
  • Metals have smaller electron affinities than nonmetals.
  • Metals have larger atoms than nonmetals.
  • 1) As you move across a period, metallic character decreases and nonmetallic character increases.

    2) As you move down a group, metallic character increases and nonmetallic character decreases.

    Semimetals (Metalloids)

  • A class of 8 elements that have properties of both metals and nonmetals.
  • B Si Ge As Sb Te Po At
    Common characteristics: