How are equations used to represent chemical reactions?Writing formulae of simple covalent molecules
All substances are described by their formulae, which are used to write balanced chemical equations. Writing the formula for an ionic compound requires knowledge of the charges on its ions.
The chemical formulaA combination of symbols that indicates the chemical composition of a substance. for a simple covalentA covalent substance is a molecule containing one or more covalent bonds (shared pairs of electrons).moleculeA collection of two or more atoms held together by chemical bonds. shows:
the symbol for each elementA substance made of one type of atom only. in the compoundA substance formed by the chemical union of two or more elements.
the number of atomThe smallest part of an element that can exist. of each element in a molecule
For example, the formula H2O shows that a water molecule contains two hydrogen atoms and one oxygen atom.