Mercury is a chemical element and the only metallic element that is liquid at standard temperature and pressure. It has many uses including in thermometers, switches, and fluorescent lights, though there are concerns about its toxicity. Mercury is also the name of the smallest planet in our solar system and a major god in Roman mythology associated with communication and trade.
2. ? MERCURY IS A CHEMICAL ELEMENT WITH THE SYMBOL HG AND ATOMIC
NUMBER 80. IT IS COMMONLY KNOWN AS QUICKSILVER AND WAS FORMERLY
NAMED HYDRARGYRUM (/HA??DR??RD??R?M/ HY-DRAR-J?R-?M).[4] A HEAVY,
SILVERY D-BLOCK ELEMENT, MERCURY IS THE ONLY METALLIC ELEMENT THAT IS
LIQUID AT STANDARD CONDITIONS FOR TEMPERATURE AND PRESSURE; THE
ONLY OTHER ELEMENT THAT IS LIQUID UNDER THESE CONDITIONS IS
THE HALOGEN BROMINE, THOUGH METALS SUCH AS CAESIUM, GALLIUM,
AND RUBIDIUM MELT JUST ABOVE ROOM TEMPERATURE.
3. ? MERCURY IS USED
IN THERMOMETERS, BAROMETERS, MANOMETERS, SPHYGMOMANOMETERS, FLO
AT VALVES, MERCURY SWITCHES, MERCURY RELAYS, FLUORESCENT LAMPS AND
OTHER DEVICES, THOUGH CONCERNS ABOUT THE ELEMENT'S TOXICITY HAVE
LED TO MERCURY THERMOMETERS AND SPHYGMOMANOMETERS BEING LARGELY
PHASED OUT IN CLINICAL ENVIRONMENTS IN FAVOR OF ALTERNATIVES SUCH
AS ALCOHOL- OR GALINSTAN-FILLED GLASS THERMOMETERS
AND THERMISTOR- OR INFRARED-BASED ELECTRONIC INSTRUMENTS. LIKEWISE,
MECHANICAL PRESSURE GAUGES AND ELECTRONIC STRAIN GAUGE SENSORS
HAVE REPLACED MERCURY SPHYGMOMANOMETERS.
4. ? MERCURY REMAINS IN USE IN SCIENTIFIC RESEARCH APPLICATIONS AND
IN AMALGAM FOR DENTAL RESTORATION IN SOME LOCALES. IT IS ALSO USED
IN FLUORESCENT LIGHTING. ELECTRICITY PASSED THROUGH MERCURY VAPOR IN
A FLUORESCENT LAMP PRODUCES SHORT-WAVE ULTRAVIOLET LIGHT, WHICH
THEN CAUSES THE PHOSPHOR IN THE TUBE TO FLUORESCE, MAKING VISIBLE
LIGHT.
? MERCURY POISONING CAN RESULT FROM EXPOSURE TO WATER-SOLUBLE FORMS
OF MERCURY (SUCH AS MERCURIC CHLORIDE OR METHYLMERCURY), BY
INHALATION OF MERCURY VAPOR, OR BY INGESTING ANY FORM OF MERCURY.
5. ? MERCURY IS A MAJOR GOD IN ROMAN RELIGION AND MYTHOLOGY, BEING ONE
OF THE 12 DII CONSENTES WITHIN THE ANCIENT ROMAN PANTHEON. HE IS THE
GOD OF FINANCIAL GAIN, COMMERCE, ELOQUENCE, MESSAGES,
COMMUNICATION (INCLUDING DIVINATION), TRAVELERS, BOUNDARIES, LUCK,
TRICKERY AND THIEVES; HE ALSO SERVES AS THE GUIDE OF SOULS TO THE
UNDERWORLD.[1][2] HE WAS CONSIDERED THE SON OF MAIA, WHO WAS A
DAUGHTER OF THE TITAN ATLAS, AND JUPITER IN ROMAN MYTHOLOGY.[
6. ? HIS NAME IS POSSIBLY RELATED TO THE LATIN WORD MERX ("MERCHANDISE";
CF. MERCHANT, COMMERCE, ETC.), MERCARI (TO TRADE),
AND MERCES (WAGES); ANOTHER POSSIBLE CONNECTION IS THE PROTO-INDO-
EUROPEAN ROOT MER?- FOR "BOUNDARY, BORDER" (CF. OLD
ENGLISH "MEARC", OLD NORSE "MARK" AND LATIN "MARG?") AND GREEK ¦¯?¦±¦¯¦²
(BY ANALOGY OF ARCT?RUS/?¦±¦ª¦³¦¯?¦±¦¯¦²), AS THE "KEEPER OF BOUNDARIES,"
REFERRING TO HIS ROLE AS BRIDGE BETWEEN THE UPPER AND LOWER WORLDS.
7. ? IN HIS EARLIEST FORMS, HE APPEARS TO HAVE BEEN RELATED TO
THE ETRUSCAN DEITY TURMS; BOTH GODS SHARE CHARACTERISTICS WITH
THE GREEK GOD HERMES. HE IS OFTEN DEPICTED HOLDING THE CADUCEUS IN
HIS LEFT HAND. SIMILAR TO HIS GREEK EQUIVALENT HERMES, HE WAS AWARDED
THE CADUCEUS BY APOLLO WHO HANDED HIM A MAGIC WAND, WHICH LATER
TURNED INTO THE CADUCEUS.
8. ? MERCURY IS THE SMALLEST AND INNERMOST PLANET IN THE SOLAR SYSTEM. ITS
ORBIT AROUND THE SUN TAKES ONLY 87.97 DAYS, THE SHORTEST OF ALL THE
PLANETS IN THE SOLAR SYSTEM. IT IS NAMED AFTER THE ROMAN DEITY MERCURY,
THE MESSENGER OF THE GODS.
? LIKE VENUS, MERCURY ORBITS THE SUN WITHIN EARTH'S ORBIT AS AN INFERIOR
PLANET, AND ITS APPARENT DISTANCE FROM THE SUN AS VIEWED FROM EARTH
NEVER EXCEEDS 28¡ã. THIS PROXIMITY TO THE SUN MEANS THE PLANET CAN ONLY BE
SEEN NEAR THE WESTERN HORIZON AFTER SUNSET OR EASTERN HORIZON BEFORE
SUNRISE, USUALLY IN TWILIGHT. AT THIS TIME, IT MAY APPEAR AS A BRIGHT STAR-
LIKE OBJECT, BUT IS OFTEN FAR MORE DIFFICULT TO OBSERVE THAN VENUS. THE
PLANET TELESCOPICALLY DISPLAYS THE COMPLETE RANGE OF PHASES, SIMILAR TO
VENUS AND THE MOON, AS IT MOVES IN ITS INNER ORBIT RELATIVE TO EARTH,
WHICH RECURS OVER ITS SYNODIC PERIOD OF APPROXIMATELY EVERY 116 DAYS.