What is the half-life of an isotope if after 30 days you have 31.25 g remaining from a 250 g beginning sample size?
a) 5 days
b) 30 days
c) 10 days
d) 2 days

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.

Sorry i dont understand the question can you rephase it?