half of the

number of

a. Normal and abnormal.

radioactive

atoms to

b. Natural and artificial.

disintegrate.

c. Alpha particles and beta particles.

d. Stable and radioactive.

d.

47.

Match each term in column A with its definition in column B.

A

B

_____ (1) Mass number.

a. One-twelfth the mass of a C12 atom.

_____ (2) Atomic mass unit.

b. The sum of electrical charges within

the atom.

_____ (3) Relative atomic

weight

c. The absolute mass, in atomic mass

units, of the most abundant isotope

of an element

d. The sum of the protons and the

neutrons of the nucleus.

e. The average mass, in atomic mass

units, of an atom's natural isotopic i-

mixture.