Sharp EL-5230 Operation Manual page 100

Chapter 8: Application Examples
Program code
T=-(ln(M≥©M≠))©
1.2118œ-4
Print T
Print"YEARS
End
• The half-life of a radioactive isotope is the time required for half of its
mass to decay.
Running the program
Press j to return to the PROG mode menu.
4.
Press 0, select the program
5.
'DECAY' and press e.
6. Enter 100 for M
Result
The half-life of
98
and 50 for M
0
14
C is 5719.980034 years.
Key operations
; T ; = S ( i
( @ v 1 z @
v 0 ) ) z 1.2118
` S 4 e
i 0 ; T e
i 1 @ a YEARS ;
e
i 5 e
.
1
T=
YEARS
DECAY :NORMAL
ORIGINAL MASS
Mº=?
5719.980034