The exponential function model of radioactive decay and the concept of a half-life are used in nuclear experiments1–4 that appear in introductory and intermediate laboratories. In our interactions with students, we have found that students at all levels have significant confusion about both the term exponential and what is meant by a half-life as well as fundamental misconceptions regarding curve fitting.

1.
Lorenzo J.
Curtis
, “
Concept of the exponential law prior to 1900
,”
Am. J. Phys.
46
,
896
906
(Sept.
1978
).
2.
B. E.
Taylor
, “
An automated short half-life experiment
,”
Am. J. Phys.
57
,
1051
1052
(Nov.
1989
).
3.
G. C.
Chikkur
and
N.
Umakantha
, “
Half-life of thorium-232: A laboratory experiment
,”
Am. J. Phys.
45
,
1120
1122
(Nov.
1977
).
4.
Byron
Curry
,
Dave
Riggins
, and
P. B.
Siegel
, “
Data analysis in the undergraduate nuclear laboratory
,”
Am. J. Phys.
63
,
71
76
(Jan.
1995
).
5.
Frank
McGeachy
, “
Radioactive decay—An analog
,”
Phys. Teach.
26
,
28
29
(Jan.
1988
).
6.
Kenneth E.
Jesse
, “
Computer simulation of radioactive decay
,”
Phys. Teach.
41
,
542
543
(Dec.
2003
).
7.
Ludwik
Kowalski
, “
Simulating radioactive decay with dice
,”
Phys. Teach.
19
,
119
(March
1981
).
8.
Stephen J.
Fairman
,
Joseph A.
Johnson
, and
Thomas A.
Walkiewicz
, “
Fluid flow with Logger Pro
,”
Phys. Teach.
41
,
345
350
(Sept.
2003
).
9.
J. R.
Smithson
and
E. R.
Pinkston
, “
Half-life of a water column as a laboratory exercise in exponential decay
,”
Am. J. Phys.
28
,
740
742
(Nov.
1960
).
10.
Driver part number—ME 8750; PASCO Cart—ME 9450; PASCO Track—ME 9453.
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