1.)Boron
2.)Cadmium has 48 electrons not 121 Mercury has 80 And Copernicum so they all have no 121 electrons
3.)Hydrogen
The answer would be 425.599 because 1 ATM is 760 mmHg.
I believe the answer is gills
Fish's use gills to breathe, so tadpoles should use gills too
hope this helps
(got the info from a documentary i watched a couple years ago)
the answer i believe is electrolytes.