214
9.
X—RAYS
and also that there is no precise meaning to be attached to
“
the;
radius of the. atom.”
It is this diffuseness, this probability of
electron position, which is emphasized in wave mechanics. The
electron may exist at a certain distance out from the nucleus, but
it may also, with lessening probability be found at other positions
on either side of the most probable location.
_
EXPERIMENT 9—1
"
._
-
__
THE ABSORPTION AND WAVE-LENGTH OF X—RAYS
(Read section 9—5 about
“
Protection from X-rays ”)
_
The purpose of this experiment is to determine the mass
—
"absorption coefcients of aluminum, iron and copper and the
,
wave-lengths of the x-rays which have passed through these
materials.
A method of successive approximations is to be used,
starting with
the known coefcients of carbon for x—rays of differ—
'
ent wave—lengths.
The absorptios screens and lter of gure 9—18 are placed over
’
.
Al
C
C
-
Fe
Cu
‘
.
-
Al_—
—/a
.—
!
!
,
i_
-
—/ F
; —
:
'
'
FIG.
X-ray abSorption screens and lter.
_
the 1_hquÔ _in- the top“rof the lead box of ‘
gure
The“lterF
;
consists “of
a sheet of Copper Which,
x—rays whose mean
WaVe‘
_,
filength
angstrom, ‘shOuld be 0.05 cent1meterthle
,
"
$
Thele"ect of thel‘ter'ontheoontinuoüs x‘-radiationis1nd1catedby
,
_
æï‘Che shaded“
area” in gurer 9'—1A;
 Thus, at a sacrice of 1ntonsltÿ,
Theappr@X1'