B the atomic number is 20 and then you subtract atomic mass to find the neutrons
There are eight protons in an Oxygen's nucleus.
The radioactive decay of unstable isotopes continually generates new energy within Earth's crust and mantle, providing the primary source of the heat that drives mantle convection. Plate tectonics can be viewed as the surface expression of mantle convection.
Answer:
molar mass (molar weight)
Explanation: