11—5.
SIMPLE RADIOACTIVE TRANSFORMATION 243
Will remain unchanged over a period of time is greater than that
_
for other nuclei.
.
'
,
_
'
.
'
The rate at which a given substance spontaneously disintegraœs
cannot be altered by any agency known to man at the present time.
.
Itis not affected by chemical réactions, pressure changes from a
good vacuum to twenty thousand atmospheres, from liquid air
temperatures up
to
three thousand degrees centigrade nor by
electric, magnetic or gravitational elds.
’
,11—5.
A Simple Radioactive Transformation—T0 illustrate
the transformation of one radioactive substance into another, a
particular Case Will be given where uranium I changes into uranium
Xl.
Uranium I, With an atomic weight of 238 and anatomie
1.0
--IQ——----—---———
:
I{ä
-
A_
_
Ëo.5
l
-
'
ê
;
:
,
_
.
%
1
!
'
°‘
!
:
.
—
.
_1_
,
,
Ï
_
_,
_.
.
,
2358 Days
'
'
_
‘—
'
'
''
’
,
F1G.
Formation and decay of uranium X1. ”
’.
of 92 isfoùnd at
off: the 'Pefiodiç Täble," As it
_
._
emits alpha rays; it
uran1umX1 SO 7tÎ}ät
always “found“ together UramumXl is °°ntmuaHY
_
mttngbtndgmmyhggtthubt .
r …
separatedfromeach°therWchemlcalmean3landPlaœd 1?,. Ÿ
chapterl7
_'