chemical elements and their compounds - Sciencemadness Dot Org

GROUP 0
INERT GASES
THE inert gases occupy a peculiar position in Chemistry. They are
practically devoid of chemical properties, and yet for that very reason
they have provided the key to the whole problem of valency and the
interpretation of the Periodic Classification.
Further, their physical behaviour, largely owing to this inertness, is of
great interest. Helium in particular shows physical properties to which
there is no parallel elsewhere, and it has opened up quite a new field of
physical investigation, that of extremely low temperature—the 'uncharted
infinity' that lies between 1° K, and the absolute zero.
The more important physical properties of the inert gases are given in
the following table.
TABLE
B.-pt. °K.
°C.
M.-pt. °K.
0 C.
(hit.T. °K.
°C.
Vol. in c.c. in
L m. 3 air«f
JIt. of evapn.
,, fusion
(k.eals./g.at.) c
M.-pt./Crit.T. 6
Trouton
Afc. Diam. in
Crystal (A)
He
4-216° a
-268-94°
..
• •
5-23° 6
-267-93°
6-24*
0-0196
0-00436
(3° K.)
• •
4-64
Ne
27-17°
-~ 245-99°
24-5 06
-248-7°
44.70&
-228-5°
1821
0-42
0-801
0-548
19-8
3-67* 3-20 3-82 3-94 4-36
:
a = \ b = 2 , c = 3 , d = \ e = B , / = 6 , g = 7 , h = 8 , i = •
A
87-92°
-185-24°
83-8° 6
-189-4°
150-69°
-122-47°
9,300
1-59
0-2808
0-556
18-1
Kr
120-9°
-63-8°
1
2138*
0-3907*
0-554
17-7
Xe
165-1°
-108-1°
161-3° c
-111-9°
289-9 0&
+ 16-7°
01
3-020
0-5485 c
0-557
18-3
Em
208°
-65°
160°
-113°
377-6°
+ 104-4°
6 XlO" 14
HELIUM
This element was discovered spectroscopically in the chromosphere of the
tun in 1868 by Loekyer and Frankland, who therefore called it helium. In
ISB5, after the discovery of argon, Ramsay found that the inactive gas which
Hlllebrand had obtained in 1890 from cleveite and other uranium minerals
by heating or solution gave the same spectrum, and so must be helium.
1 G. Schmidt and W. H. Keesom, Physica, 1937, 4, 963.
1 K. Clusius and K. Weigand, Z.physikal. Chem, 1939, B 42, 111.
8 K. Clusius and L. Riccoboni, ib. 1938, B 38, 81.
* JB. Justi, Phys. Z. 1935, 36, 571.
1 K. Clusius, A. Kruis, and F. Konnertz, Ann, Phys, 1938, [v] 33, 642.
fl F. A. Paneth, Nature, 1937, 139, 181.
f H. GUiokauf, Proc. Boy. Soc. 1946, 185, 98.
1 W. H. Keesom and K. W. Taoonis, Proc, K. Ahad. Amst. 1938, 41, 95.
• K. Glusiui, Z, physikal Ch&m, 1936, B 31, 459.