H' at. wt. (natural) 1.007967
at. wt. (H') 1.007822
at. no. 1
m.p. - 259.140C
b.p. - 252.870C
density 0.08988 gm./l
density (liquid) 70.8 gm/i. (-2530C)
density (solid) 7016 gm/i. (-2620C)
valence 1.
Electronic configuration
| K |
L |
M |
N |
O |
P |
Q |
| 1 |
2 |
3 |
4 |
5 |
6 |
7 |
| s |
s p |
s p d |
s p d f |
s p d f |
s p d f |
s p d f |
| 1 |
|
|
|
|
|
|
. MERCURY (Planet Mercury), Hg (hydragyrim, liquid
silver); at. wt. 200.59, at. no.80; m~p. 38.870.C; b~p.
356.580C; sp. gr. 13.546 (2rnC); valence 1 or 2. Known to
ancient Chinese and Hindus; found in Egyptian tombs of
1500 B.C. Mercury is the only common metal liquid at
ordinary temperatures. It only rarely occurs free in nature.
The chief ore is cinnabar (HgS). Spain and Italy produce
about 50% of the world's supply of the metal. The com-
mercial unit for handling mercury is the "flask," which
weighs 76 lbs. The metatis obtained by heating cinnabar in
a current'of air~and by~condensing the vapor. It is a heavy,
silvery white metal; a rather poor conductor of heat, as
compared with other metals; and a fair conductor of elec-
tricity. The metal is widely used in laboratory work for
making thermometers, barometers, diffusion pumps, and
many other instruments. It is used in making mercury-vapor
lamps and advertising signs, etc., and is used in mercury
switches and other electrical apparatus. Other uses are for
making pesticides, mercury cells for caustic-chlorine pro-
duction, dental preparations, anti-fouling paint, batteries,
and catalysts. The most important salts are' mercuric chloride
(HgCl2, corrosive sublimate-a violent poison), mercurous
chloride Hg2Cl2 (calomel- occasionally still used in med-
icine), mercury fulminate '(Hg(ONC)2, a detonator widely
used in explosives), and mercuric sulfide (Hg$, vermillion,
a high-grade paint pigment). Organic mercury compounds
are important. It has been found that an electrical discharge
causes mercury vapor to combine with neon, argon, krypton,
and xenon. These products, held together with van der
Waals' forces, correspond to HgNe, HgAr, HgKr, and
HgXe. It is not generally appreciated that mercury is a
virulent prison and is readily absorbed through the respic-
atory tract, the gastrointestinal tract, or through unbroken
skin. It acts as a cumulative poison since only small amounts
of the element can be eliminated at a time by the human
organism. The maximum allowable concentration of mer-
cury vapor in air has been set at 0.1 mg./cu. meter. Since
B-20
mercury is a very volatile element, dangerous levels are
readily attained in air. Air saturated with mercury vapor'at
200C contains a concentration which exceeds the toxic limit
by more than 100 times. The danger increases at higher
temperatures. It is therefore important that mercury be
handled with utmost care. Containers of mercury should be
securely covered and spillage should be avoided. If it is
necessary to heat mercury or mercury compounds, it should
be done in a well-ventilated hood.
© 1999 F. Davies
Delphi O.E.M. Co.
All rights reserved
Return to periodic table