Part b using the mass of the proton 1.0073 amu and assuming its diameter is 1.0×10−15m, calculate the density of a proton in g/cm3.

Assuming that the proton is in the shape of the sphere, let's calculate first its volume in units of cm³:

Volume of sphere = 4/3*πr³
Volume of sphere = 4/3*π{[(1.0×10⁻¹⁵ m * 100 cm/1m)]/2}³
Volume = 5.236×10⁻⁴⁰ cm³

The density is then equal to:
Density of proton = 1.0073 g/5.236×10⁻⁴⁰ cm³
Density = 1.924×10³⁹ g/cm³

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.