364 tL: A. Hill—Notes on Argon and Heliwm. 
ae Metalloids —~ —— Metals —., 
H O F A Cl Na He 
i 14 16 19 20 35°5 23 200 
gas gas gas gas gas gas solid liquid 
colorless colorless colorless ereenish colorless greenish yellow white white 
electro neg. electro neg. electroneg. electro neg. ? electro neg. | electro pos. electro po 
Sp. Gr. 2 265 15 1°33 39 13-6 
Mer. — 214° below ) —189°6 —102° 95:5, —38°5 
B. P. —243° —194° —182-7° —'95° ¢ —187: —33°6° red heat +4357:25 
At Vol 15°5 14° 15°5? 13°3 25°6 23°5 14:1 
Evidently argon has the characteristics of a metalloid rather 
than of a metal. 
Now of these bodies, fF’, Cl, and O at ordinary temperatures 
exhibit the strongest tendencies known for combination with 
other substances, and H and N, in the nascent state, are almost 
equally endowed with chemical energy, but this energy is 
masked so to speak, gradationally, by the force holding the 
atoms together in the molecule which acts against and in oppo- 
sition to the force tending to cause chemical combination. 
This opposing force of aggregation, comparatively weak in F, 
is stronger in Cl and QO, still stronger in H, very much stronger 
in N, and why not also, let us say, even stronger yet in argon 3 
thus accounting for its chemical inertness. 
Indeed, is there any good ground, reasoning from the known 
properties of these elements (if it be an element), for believing 
argon to be in such a different physical condition from the 
rest of them, as is implied in the assumption that it is too hot 
to combine with other elements? 
The discoverers in their memoir have remarked, that “‘ the 
chemical behavior of nitrogen is such as to suggest that its 
dissociated atoms would possess a high degree of activity, and 
that even though they might be formed in the first instance 
their life would probably be short.” Could not this language 
with great propriety be applied to its analogue, argon, also? 
The theory, upon which argon at ordinary temperatures is 
considered to be in the same physical condition as mereury at 
800°, is probably somewhat as follows: Starting with the ele- 
ments in the solid state at the absolute zero of temperature, 
and devoid of energy or tendency towards chemical combina- 
nation with other bodies, as temperature increases they finally 
become liquid and then gaseous. The increasing affinity 
toward other bodies increases with liquefaction, and still more 
so when the elements are vaporized; finally the heat becomes 
sufficient to dissociate the molecules into free atoms, in which 
state the tendency. towards chemical combination is at its maxi- 
mum, because the opposing force of molecular aggregation is 
reduced to zero. From this point on, an increase in tempera- 
ture decreases the affinity towards ’ other substances, until 
finally we arrive at a temperature above which the repulsive 
atin — See a bare age A we Wii tanta int 
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