Changes

The shell corresponding to the highest value of principal quantum number in the atom. The valence electrons in this shell are on average farther from the nucleus than other electrons; they are often directly involved in chemical reaction.<ref>http://antoine.frostburg.edu/chem/senese/101/electrons/glossary.shtml</ref>

The '''valence shell''' is the [[electron shell]] which corresponds to the highest value of principal [[quantum number]] in an [[atom]]. The valence [[electron]]s in this shell are on average farther from the [[nucleus]] than other electrons; these are electronc which are directly involved in [[chemical reaction]]s.<ref>http://antoine.frostburg.edu/chem/senese/101/electrons/glossary.shtml</ref>

[[Category:Chemistry]]

[[Category:Chemistry]]