What's the difference between Na+ and Na?

JFT 4/25/99

ionic compound*
valence electrons*
valence shell*
Ions have properties that are completely different from those of their parent atoms. Chemical change usually involves the valence electrons. Ionization changes the number of electrons in the valence shell and so has a strong effect on chemical behavior.

In the case of sodium, ionizing the atom completely removes the 3s valence shell. The remaining electrons are tightly bound and require far more energy to remove. As a result, the sodium ion is far more inert than the sodium atom.

Table Some differences in chemical and physical properties for sodium ion and sodium atom.
Property Na atom Na+ ion
charge neutral (0) positive (+1)
electronic configuration 1s22s22p63s1 1s22s22p6
pure form soft, shiny metal not found pure; must be combined with anions to form stable ionic compounds
reaction with water violent exothermic reaction with water forms Na+(aq), OH-(aq), H2(g) Na+ dissolves in water without further reaction
reaction with hydrogen gas 2 Na(s) + H2(g) rightarrow 2 NaH(s) no reaction
reaction with oxygen gas 2 Na(s) + O2(g) rightarrow Na2O2(s) no reaction
reaction with alcohol 2 Na(s) + 2 C2H5OH(ell)
rightarrow 2 NaOC2H5 + H2(g)
no reaction
conductivity Na(s) is an excellent conductor of heat and electricity Na+ solid compounds are poor conductors of heat and electricity; Na+ in aqueous solution conducts electricity

Author: Fred Senese senese@frostburg.edu

General Chemistry Online! What's the difference between Na^+^ and Na?

Copyright © 1997-2010 by Fred Senese
Comments & questions to fsenese@frostburg.edu
Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/atoms/faq/print-sodium-ion-vs-atom.shtml