What is the total number of molecules of hydrogen in .25 moles of hydrogen

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.

Rn in the right answer

In any atom of any element, you will find protons and neutrons in the nucleus of any atom 

Answerlimiting reactant;