Question

Is removing an electron from lithium exothermic?

Removing an electron from lithium would decrease its potential energy and release energy since it would then have a noble gas configuration. I know it takes ionization energy to take that electron away, but isn't the amount of energy released from the decrease in potential energy greater than the ionization energy?

Answer 1

It does give an ENDOTHERM....

Explanation:

Would you not expect on the basis of simple electrostatics...that..

`Li(g) +Delta rarr Li(g)^+ + e^-`

..should be endothermic, given that we have to separate an electron from a positively charged nucleus?

And as scientists, we should examine the data...

This site gives `Delta_"ionization"=520.2*kJ*mol^-1`...this is more energetic than that of SODIUM, `Delta_"ionization"=495.8*kJ*mol^-1` BUT LESS ENERGETIC than that of BERYLLIUM, `Z=4`, `Delta_"ionization"=899.5*kJ*mol^-1`. As is ALWAYS observed, ionization enthalpies INCREASE across a Period from left to right as we face the Table, but DECREASE down a Group, a column of the Periodic Table. Capisce?

How would you expect the SECOND IONIZATION ENERGY to evolve? Would it be the same, more or less?

`Li^(+)(g)+Delta_2rarr Li^(2+)(g)+ e^(-)`