What's the difference between Na⁺ and Na?

JFT 4/25/99

	Vocabulary
	anion exothermic 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) 2 NaH(s)	no reaction
reaction with oxygen gas	2 Na(s) + O2(g) Na2O2(s)	no reaction
reaction with alcohol	2 Na(s) + 2 C2H5OH() 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

Copyright © 1997-2010 by Fred Senese
Comments & questions to fsenese@frostburg.edu
Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101/atoms/faq/sodium-ion-vs-atom.shtml