NSCI 1322 Lecture Notes - Lecture 7: Chromium Trioxide, Silicon Dioxide, Sulfur Dioxide
12 Jan 2017
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Document Summary
Solids at (except , which is a liquid) Solids or gases at (except , which is a liquid) Nonconductors of heat and electricity (except the allotropes graphite and graphene) Oxides are basic (unless metal is in a high. The metallic elements generally have low ionization energies and low electronegativities compared with the nonmetallic elements. As a result, the metals tend to lose their valence electrons to form cations. Nonmetals, on the other hand, form monatomic anions and oxoanions. Oxides of metals in high oxidation states, which you encounter in some transition metals, can be acidic; chromium(vi) oxide is an acidic oxide. The oxides of the nonmetals are acidic. Sulfur dioxide, an oxide of a nonmetal, dissolves in water to form an acidic solution. Silicon dioxide (silica sand) does not dissolve in water, but it does react when melted with basic oxides such as calcium oxide to form salts.
