Basic Concept in Chemistry - Chemical Formulae and Name of Compounds

In order to make it easier to describe elements, molecules, and compound, chemical formulae are used.

A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound.

The chemical formula identifies each constituent element by its chemical symbol and indicates the number of atoms of each element found in each discrete molecule of that compound.

If a molecule contains more than one atom of a particular element, this quantity is indicated using a subscript after the chemical symbol and also can be combined by more chemical elements.

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For example, methane, a small molecule consisting of one carbon atom and four hydrogen atoms, has the chemical formula CH₄.
The sugar molecule glucose has six carbon atoms, twelve hydrogen atoms and six oxygen atoms, so its chemical formula is C₆H₁₂O₆.

 
The graphic below illustrates the formula for water using symbols.

 http://www.ndt-ed.org/EducationResources/HighSchool/Radiography/chemicalformula.htm

Review: 

1. Chemical formulas are used to describe the types of atoms and their numbers in an element or compound.
2. The atoms of each element are represented by one or two different letters.
3. When more than one atom of a specific element is found in a molecule, a subscript is used to indicate this in the chemical formula.

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Chemical Formula and Names Worksheet