* Semimetals have intermediate properties: They exhibit properties of both metals and nonmetals, making their bonding behavior less predictable.
* Tendency to form network solids: Semimetals often prefer to form extended network solids with covalent bonds throughout the structure. This is due to their ability to form both metallic and covalent bonds.
* Examples of molecular compounds:
* Arsenic trioxide (As₂O₃): This compound contains discrete As₂O₃ molecules held together by covalent bonds.
* Silicon dioxide (SiO₂): While primarily known as a network solid, it can exist in molecular forms like silica (SiO₂) with covalent bonds.
* Germanium tetrachloride (GeCl₄): This compound exists as discrete molecules.
However, compared to the vast array of molecular compounds formed by nonmetals (like water, carbon dioxide, ammonia), the number of molecular compounds containing semimetals is relatively limited.
In summary, semimetals can form molecular compounds, but their ability to form extended network solids makes this less common compared to their tendency to form network structures.
