How many moles of H2O are in 12.00 kg of water?

Why doesn't heat added to water make the tempature rise above 100c

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule