Which metal will need the most energy per million atoms to boil it?

Oh, dude, that's a great question! So, technically speaking, tungsten would require the most energy per million atoms to boil because it has the highest boiling point of any metal. It's like the diva of the Periodic Table, demanding all the energy to make it budge. So, if you're ever in a boiling competition with metals, bet on tungsten to take its sweet time heating up!