Substances with multiple covalent bonds
Giant covalent structures
A bond between atoms formed when atoms share electrons to achieve a full outer shell of electrons. leads to the formation of simple A collection of two or more atoms held together by chemical bonds., which contain a small number of The smallest part of an element that can exist.. It can also lead to the formation of giant A covalent substance is a molecule containing one or more covalent bonds (shared pairs of electrons). structures, which contain very many atoms.
Silica is the main A substance formed by the chemical union of two or more elements. found in sand. It contains silicon and oxygen atoms joined together to form a giant covalent structure. The atoms have a regular, repeating arrangement called a giant covalent A regular grid-like arrangement of atoms in a material..
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Chemical formulae
Unlike simple molecules, giant covalent structures do not contain fixed numbers of atoms. This means that the chemical formula used for a giant covalent substance is its The simplest whole number ratio of the atoms of each element in a compound.. An empirical formula is the simplest whole number ratio of the atoms of each element in the substance. For example, the formula for silicon oxide is SiO2. It shows that there are two oxygen atoms for every silicon atom in the structure of silicon oxide, which is why it is often called silicon dioxide.
Polymers
Simple A large molecule formed from many identical smaller molecules known as monomers. consist of large molecules that contain chains of carbon atoms. Like giant covalent structures, simple polymer molecules contain varying numbers of atoms. A typical poly(ethene) molecule may contain thousands of carbon atoms joined together in a chain.