'_
_
10—4.
ÎSÔTÔPËS
'
227
fering velocities are all brought to the same ”focal point,” thus
”reducing the exposure times and assuring ne
Rays with
different values of charge to mass ratio come to differth focal lines.
“
12/13
|4/ |5 l6-,/
17
_'
c\ CH\
CHs\
o‘\cr—u
FIG. 10—4.
The mass spectrum of méthane,
_
The photographie records 5 show sections of the lines,as indicated in gure 10—4.
‘
_
10—4.
Isotopes.——In 1913, Thomson studied the parabolas
produced by the ghter gaseé. He observed a line at mass 22 which
could not be identied with any known substance in the discharge
-
tube.
At rst he thought the line might be a second order line of
carb0n dioxide (C02'H‘) but soon found that it persisted after
eliminating this gas and itsstrong rSt order line. However, he —
found that the_lineÿalwaiys appeared When nebn was present in the
discharge. The atomic weight. of neon, as determined by chemical
-
means is 20.183."_It Was, nevertheless, thought that the
22
was caused byn'eon‘.
.—
,
”
»
—
With
lines; Aston was able Ïto
ann0unce' 6…in
neon, one of:atomic
weight 20 and the
of thesezsaæpes are
’
They
Isot0peswlbepresentedmchapterlîAfterthedlS°°V6rYof » -
mentFmtheevacuatedchamber®fgure10—5areusedtowmze
-
Ï
gasesorvap@rspr@duœdbÿheatmasehdmthesmalleïectmaï :
"
0Vf=nTheposmvelnswhlcharethuspmduœdafedfawnto
+
_
10—4.
ÎSÔTÔPËS
'
227
fering velocities are all brought to the same ”focal point,” thus
”reducing the exposure times and assuring ne
Rays with
different values of charge to mass ratio come to differth focal lines.
“
12/13
|4/ |5 l6-,/
17
_'
c\ CH\
CHs\
o‘\cr—u
FIG. 10—4.
The mass spectrum of méthane,
_
The photographie records 5 show sections of the lines,as indicated in gure 10—4.
‘
_
10—4.
Isotopes.——In 1913, Thomson studied the parabolas
produced by the ghter gaseé. He observed a line at mass 22 which
could not be identied with any known substance in the discharge
-
tube.
At rst he thought the line might be a second order line of
carb0n dioxide (C02'H‘) but soon found that it persisted after
eliminating this gas and itsstrong rSt order line. However, he —
found that the_lineÿalwaiys appeared When nebn was present in the
discharge. The atomic weight. of neon, as determined by chemical
-
means is 20.183."_It Was, nevertheless, thought that the
22
was caused byn'eon‘.
.—
,
”
»
—
With
lines; Aston was able Ïto
ann0unce' 6…in
neon, one of:atomic
weight 20 and the
of thesezsaæpes are
’
They
Isot0peswlbepresentedmchapterlîAfterthedlS°°V6rYof » -
mentFmtheevacuatedchamber®fgure10—5areusedtowmze
-
Ï
gasesorvap@rspr@duœdbÿheatmasehdmthesmalleïectmaï :
"
0Vf=nTheposmvelnswhlcharethuspmduœdafedfawnto
+