Describe the number of neutrons in atom of cl-37

Protons equals atomic number which is 17
the atomic mass for chlorine is 37 (because it says cl-37) 
in-order to find the number of neutrons
neutrons= atomic mass- number of protons
37-17=20

therefore 20 neutrons

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.