CK-12 Physical Science Concepts - For Middle School

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 3. Chemical Interactions


FIGURE 3.9


Summary



  • Ionic compounds consist of oppositely charged ions that are held together by ionic bonds. The opposite
    charges cancel out so ionic compounds have a net neutral charge. Ionic compounds form when metals transfer
    valence electrons to nonmetals.

  • Ionic compounds exist as crystals rather than molecules. A crystal consists of many alternating positive and
    negative ions bonded together in a matrix.

  • Ionic compounds are named for their positive metal ion first, followed by their negative nonmetal ion.

  • Ionic compounds are solids with high melting and boiling points. They are good conductors of electricity but
    only when dissolved in water. Their crystals are rigid and brittle.

  • Ionic compounds have many uses in industry. They are also needed by humans and other living things.


Vocabulary



  • crystal: Rigid, lattice-like framework of many ions bonded together that is formed by some compounds such
    as table salt (NaCl).

  • ionic compound: Compound that forms when oppositely charged metal and nonmetal ions are held together
    in a crystal by ionic bonds.

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