How can you determine the atomic mass ? will give crown

To determine the atomic mass, we have to add the neutrons and protons that is present in the atom.

Explanation:

An atom’s atomic mass is defined as the whole number of neutrons and protons present in atom. To stabilize the atom number of electron and the proton is the same. The protons carry positive charge, the electron Carriers negative charge and the neutron are neutral in nature and are chargeless.

All the elements present in the atom have mass. All the elements are added to get the mass of atom. According to the shape and presence of protons the atomic mass is differed.  

b. lithosphere, asthenosphere, mesosphere   is the answer most likely