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International System of Units (view source)
Revision as of 18:49, September 12, 2008
, 18:49, September 12, 2008→Mole
The '''mole''' (symbol mol) is the unit of [[amount of substance]]. Its definition depends on that of the kilogram. It is that mass of any substance having as many ''elementary entities'' of that substance as are to be counted in 12 grams of [[carbon]]-12. An ''elementary entity'' is either an [[atom]] or a [[molecule]]--but for an [[ionic compound]], the number of elementary entities is the total number of [[cation|cations]] and [[anion|anions]] required to make the compound electrically neutral.
The '''mole''' (symbol mol) is the unit of [[amount of substance]]. Its definition depends on that of the kilogram. It is that mass of any substance having as many ''elementary entities'' of that substance as are to be counted in 12 grams of [[carbon]]-12. An ''elementary entity'' is either an [[atom]] or a [[molecule]]--but for an [[ionic compound]], the number of elementary entities is the total number of [[cation|cations]] and [[anion|anions]] required to make the compound electrically neutral.
[[Avogadro's number]] gives the required number of elementary entities, and is represented by the letter L. L has the approximate value of 6.022X10<sup>23</sup>
[[Avogadro's number]] gives the required number of elementary entities, and is typically represented by ''N<sub>A</sub>''. ''N<sub>A</sub>'' has the approximate value of 6.022X10<sup>23</sup>
Effectively, one mole of any substance is its formula mass in grams.
Effectively, one mole of any substance is its formula mass in grams.