CK-12 Physical Science - For Middle School

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 7. Chemical Bonding


FIGURE 7.14


A blacksmith shapes a piece of iron.

FIGURE 7.15


The girders of this bridge are made of
steel.

Lesson Summary



  • A metallic bond is the force of attraction between a positively charged metal ion and the valence electrons
    it shares with other ions of the metal. The electrons move freely around the positive ions, which form a
    lattice-like structure.

  • With freely moving electrons, metals are good conductors of electricity. The positive ions of metals can also
    move within the "sea" of electrons without breaking the metallic bonds that hold them together. This allows
    metals to change shape without breaking.

  • Pure metals may be less useful than mixtures of metals, called alloys. Examples of alloys include steel, bronze,
    and brass.

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