How do scientists determine the number of neutrons in an isotope of an atom?

a.
they find the number of protons.

b.
they divide the atomic mass by two.

c.
they add the number of electrons and protons.

d.
they subtract the atomic number from the atomic mass.

my best guess would be c, but i'm not sure.

show the wavelengths of a wave. show the crests of a wave.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.