Na(s) ===> Na(g)
isnt it when a mole of gaseous ions is formed from an element in its standard state?
And also what is the diff between atomisation and bond dissociation.
e.g Cl2(g) ==> 2Cl(g) and 1/2Cl2(g)==>Cl
Both require the breakage of double bond?
And why is the enthalpy of atomisation = 1/2(enthalpy of dissociation)