30
2 Radioactivity
Fig. 2.9 Growth and decay
of Lanthanum-140 from
freshly separated
Barium-140 and decay of the
Barium-140 as a function of
time
Total Activity
Daughter
Log (activity, cpm)
Time (d)
0
8
16
24
Parent
140
La
140 Ba
(t 1/2 40 h)
(t 1/2 12.8 d)
Fig. 2.10 Decay of
Polonium-218 to Lead-214
Total activity
Daughter
Parent
(Polonium-218)
Log of activity
(Lead-214)
Time (min)