A chemical formula is a way that chemists describe a molecule. The formula says what atoms, and how many of each type, are in the molecule. Sometimes the formula shows how the atoms are linked, and sometimes the formula shows how the atoms are arranged in space.

The letter shows what chemical element each atom is.^[1] The subscript shows the number of each type of atom. For example, hydrogen peroxide has the formula H₂O₂. Methane has one carbon (C) atom and four hydrogen atoms; the chemical formula is CH₄. The sugar molecule glucose has six carbon atoms, twelve hydrogen atoms, and six oxygen atoms, so its chemical formula is C₆H₁₂O₆.

Chemical formulas are used in chemical equations to describe chemical reactions.

The 19th-century Swedish chemist Jöns Jacob Berzelius worked out this system for writing chemical formulas.

2 atoms of hydrogen and 1 atom of oxygen can produce 1 molecule of water

Reading and writing formulas |

Chemical formulas are another way to represent the number of atoms.^[2] Chemical formulas are used to represent kinds of atoms in a combination. Chemical formulas use subscripts to tell how many of each atom are present in a combination. Subscripts are small numbers to the lower right of a symbol. They represent the number of atoms of that element in the equation. Before writing Chemical formulas, write down the symbol of each atom present in your equation. Writing chemical formula is a way of informing the chemical figure. It is most easily found in the periodic table. The periodic table is a chart of all well-known parts. Use the periodic table to reference the figure that cannot be remembered.^[3]

Element families |

The five element families

Different elements are found in the periodic table. Each element has a family. An element family is an arrangement of elements. This element family has common properties. They are sharing the same characteristics.

Elements are displayed in order. Each element is put into families. There are three main categories such as metals, nonmetals, and semimetals.^[4] Each element family is displayed by the number of electrons in the outer shell. They can also display the same properties and valence electrons.

Related pages |

• Chemical equation

References |

1. 
   ↑ "chemical elements". Retrieved june 8 2016. Check date values in: |accessdate= (help).mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"""""""'""'".mw-parser-output .citation .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;color:#33aa33;margin-left:0.3em.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em
   


2. 
   ↑ "Chemical Formula and their Arithmetic". Retrieved June 6 2016. Check date values in: |accessdate= (help)
   


3. 
   ↑ Ralph S. Petrucci, William S. Harwood, F. Geoffrey Herring (2002). "3". General Chemistry: Principles and Modern Applications (8th ed.). Prentice-Hall. ISBN 0131988255. ASIN B000ZI5Z2K.CS1 maint: Multiple names: authors list (link)
   


4. 
   ↑ "Element Families". Retrieved June 6 2016. Check date values in: |accessdate= (help)