A student is trying to explain what an atomic mass unit is to his classmate. Help him select a solid definition.
A. An atomic mass unit, or amu, is the total number of protons in an atom that can be used to identify the element.
B. An atomic mass unit, or amu, is also called a 'dalton' and it is equal to 1/12 the mass of a carbon-14 atom.
C. An atomic mass unit, or amu, is also called a 'dalton' in life science studies and it is the same thing, roughly, as a proton or neutron and is 1/12 the mass of a carbon-12 atom.
D. An atomic mass unit, or amu, is the same as the weighted average mass of an atom and is found by measuring all the isotopes known of the element in question.