radioactive

43. Match each tem in column A with its definition in column B.

stable

A

B

_____ (1) Mass number.

a. The sum of electrical charges within

the atom.

_____ (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.

(1) d.

44.

State the definition of an isotope.

(2) e.

(3) c.