Chemical Formula and Equations

Chemical Formula and Equations - What is a Chemical Formula?
Chemical Formulas are a type of shorthand for representing the elements in a compound. Element Symbols are included on the Periodic Table. Chemical symbols (Element symbols) from the periodic table are used for the individual elements e.g. H for hydrogen, C for carbon, O for oxygen, N for nitrogen, Ca for calcium and Na for Sodium. Substances that have two or more atoms bonded together, and therefore more than one element e.g. H₂O are called compounds. See Examples of Compounds.

Chemical Formula and Equations - Subscripts
A chemical formula or equation shows the symbols of the elements in the compound and the ratio of the elements to one another. If a substance contains more than one atom of a particular element, this quantity is indicated in chemical formulas or equations using a subscript number after the element symbol. The subscript number refers only to the element it immediately follows. For example, the chemical formula for water is H₂O which indicates that 2 atoms of Hydrogen combines with 1 atom of oxygen.

How to write a Chemical Formula or Equation using Subscripts
To type or write a subscript for a chemical formula or equation just follow these simple instructions:

• Type in the formula or equation for example H2O

• Highlight the number

• Click Format

• Select Font... Decrease the font size of the number

• Under the heading Effects tick the Subscript Box

• The formula will now show the equation with the number in subscript - H₂O

Chemical Formula and Equations

Chemical Formula and Equations - Examples and Meanings of Subscripts
For example, the chemical formula for water is H2O which indicates that 2 atoms of Hydrogen combines with 1 atom of oxygen. The chemical formula for sodium chloride (Salt) is NaCl indicating that one atom of sodium combines with one atom of chlorine in a one-to-one ratio. Subscripts are added, following the element symbol, to indicate that the number of atoms of that element in the compound if it is greater than one. For example, the formula for magnesium bromide MgBr2 which indicates that one magnesium atom combines with two bromine atoms.

Meanings and Examples of Chemical Formula and Equations
The following examples of Chemical Formula and Equations explain their meaning.

Example of Chemical Formula for Salt (Sodium Chloride) - NaCl

NaCl

Symbol Na indicates the element Sodium
Symbol Cl indicates the element Chlorine
No subscripts indicate only 1 atom for each element              

Example of Chemical Formula for Water - H₂O

H₂O

Symbol H indicates the element Hydrogen
Symbol O indicates the element Oxygen
Subscript indicates 2 atoms of Hydrogen

Chemical Formula and Equations - Common Chemical Formula List
The following list of Chemical Formula and Equations shows some of the most common chemical formulas.

Chemical Formula and Equations
The above list of Chemical Formula and Equations provides details of the common Chemical Formulas.

Chemical Formula and Equations - Elements Map!
For additional information about the elements featured on the Periodic Table please refer to our comprehensive Elements Map!