43. Match each tem in column A with its definition in column B.
_____ (1) Mass number.
a. The sum of electrical charges within
_____ (2) Atomic mass unit.
b. The absolute mass, in
_____ (3) Relative atomic weight
atomic mass units, of the most
abundant isotope of an element.
c. The average mass, in atomic mass
units, of an atom's natural isotopic
d. The sum of the protons and the
e. One-twelfth the mass of a C12 atom.
State the definition of an isotope.