| slovo | definícia |
platinum
(mass) | platinum
- platina |
platinum
(encz) | platinum,platina [chem.] kov web |
Platinum
(gcide) | Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
silver, LL. plata a thin plate of metal. See Plate, and cf.
Platina.] (Chem.)
A metallic element of atomic number 78, one of the noble
metals, classed with silver and gold as a precious metal,
occurring native or alloyed with other metals and also as the
platinum arsenide (sperrylite). It is a heavy tin-white metal
which is ductile and malleable, but very infusible (melting
point 1772[deg] C), and characterized by its resistance to
strong chemical reagents. It is used for crucibles in
laboratory operations, as a catalyst, in jewelry, for stills
for sulphuric acid, rarely for coin, and in the form of foil
and wire for many purposes. Specific gravity 21.5. Atomic
weight 195.1. Symbol Pt. Formerly called platina.
[1913 Webster +PJC]
Platinum black (Chem.), a soft, dull black powder,
consisting of finely divided metallic platinum obtained by
reduction and precipitation from its solutions. It absorbs
oxygen to a high degree, and is employed as an oxidizer.
Platinum lamp (Elec.), a kind of incandescent lamp of which
the luminous medium is platinum. See under Incandescent.
Platinum metals (Chem.), the group of metallic elements
which in their chemical and physical properties resemble
platinum. These consist of the light platinum group, viz.,
rhodium, ruthenium, and palladium, whose specific
gravities are about 12; and the heavy platinum group,
viz., osmium, iridium, and platinum, whose specific
gravities are over 21.
Platinum sponge (Chem.), metallic platinum in a gray,
porous, spongy form, obtained by reducing the double
chloride of platinum and ammonium. It absorbs oxygen,
hydrogen, and certain other gases, to a high degree, and
is employed as an agent in oxidizing.
[1913 Webster] |
platinum
(wn) | platinum
n 1: a heavy precious metallic element; grey-white and resistant
to corroding; occurs in some nickel and copper ores and is
also found native in some deposits [syn: platinum, Pt,
atomic number 78] |
platinum
(elements) | platinum
Symbol: Pt
Atomic number: 78
Atomic weight: 195.078
Attractive greyish-white metal. When pure, it is malleable and ductile.
Does not oxidize in air, insoluble in hydrochloric and nitric acid.
Corroded by halogens, cyanides, sulphur and alkalis. Hydrogen and
oxygen react explosively in the presence of platinum. There are six
stable isotopes and three radioisotopes, the most stable being Pt-193
with a half-life of 60 years. Platinum is used in jewelry, laboratory
equipment, electrical contacts, dentistry, and anti-pollution devices in
cars. PtCl2(NH3)2 is used to treat some forms of cancer.
Platinum-cobalt
alloys have magnetic properties. It is also used in the definition of
the Standard Hydrogen Electrode. Discovered by Antonio de Ulloa in South
America in 1735. The name comes from the Spanish word platina which
means
silver. Platinum metal is generally not a health concern due to its
unreactivity, however platinum compounds should be considered highly
toxic.
|
| | podobné slovo | definícia |
platinum
(mass) | platinum
- platina |
platinum
(encz) | platinum,platina [chem.] kov web |
platinum black
(encz) | platinum black,platinová čerň n: Clock |
platinum-blonde
(encz) | platinum-blonde, adj: |
platinum silicide
(czen) | Platinum Silicide,PiSi[zkr.] [voj.] Zdeněk Brož a automatický překlad |
Platinum black
(gcide) | Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
silver, LL. plata a thin plate of metal. See Plate, and cf.
Platina.] (Chem.)
A metallic element of atomic number 78, one of the noble
metals, classed with silver and gold as a precious metal,
occurring native or alloyed with other metals and also as the
platinum arsenide (sperrylite). It is a heavy tin-white metal
which is ductile and malleable, but very infusible (melting
point 1772[deg] C), and characterized by its resistance to
strong chemical reagents. It is used for crucibles in
laboratory operations, as a catalyst, in jewelry, for stills
for sulphuric acid, rarely for coin, and in the form of foil
and wire for many purposes. Specific gravity 21.5. Atomic
weight 195.1. Symbol Pt. Formerly called platina.
[1913 Webster +PJC]
Platinum black (Chem.), a soft, dull black powder,
consisting of finely divided metallic platinum obtained by
reduction and precipitation from its solutions. It absorbs
oxygen to a high degree, and is employed as an oxidizer.
Platinum lamp (Elec.), a kind of incandescent lamp of which
the luminous medium is platinum. See under Incandescent.
Platinum metals (Chem.), the group of metallic elements
which in their chemical and physical properties resemble
platinum. These consist of the light platinum group, viz.,
rhodium, ruthenium, and palladium, whose specific
gravities are about 12; and the heavy platinum group,
viz., osmium, iridium, and platinum, whose specific
gravities are over 21.
Platinum sponge (Chem.), metallic platinum in a gray,
porous, spongy form, obtained by reducing the double
chloride of platinum and ammonium. It absorbs oxygen,
hydrogen, and certain other gases, to a high degree, and
is employed as an agent in oxidizing.
[1913 Webster] |
Platinum lamp
(gcide) | Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
silver, LL. plata a thin plate of metal. See Plate, and cf.
Platina.] (Chem.)
A metallic element of atomic number 78, one of the noble
metals, classed with silver and gold as a precious metal,
occurring native or alloyed with other metals and also as the
platinum arsenide (sperrylite). It is a heavy tin-white metal
which is ductile and malleable, but very infusible (melting
point 1772[deg] C), and characterized by its resistance to
strong chemical reagents. It is used for crucibles in
laboratory operations, as a catalyst, in jewelry, for stills
for sulphuric acid, rarely for coin, and in the form of foil
and wire for many purposes. Specific gravity 21.5. Atomic
weight 195.1. Symbol Pt. Formerly called platina.
[1913 Webster +PJC]
Platinum black (Chem.), a soft, dull black powder,
consisting of finely divided metallic platinum obtained by
reduction and precipitation from its solutions. It absorbs
oxygen to a high degree, and is employed as an oxidizer.
Platinum lamp (Elec.), a kind of incandescent lamp of which
the luminous medium is platinum. See under Incandescent.
Platinum metals (Chem.), the group of metallic elements
which in their chemical and physical properties resemble
platinum. These consist of the light platinum group, viz.,
rhodium, ruthenium, and palladium, whose specific
gravities are about 12; and the heavy platinum group,
viz., osmium, iridium, and platinum, whose specific
gravities are over 21.
Platinum sponge (Chem.), metallic platinum in a gray,
porous, spongy form, obtained by reducing the double
chloride of platinum and ammonium. It absorbs oxygen,
hydrogen, and certain other gases, to a high degree, and
is employed as an agent in oxidizing.
[1913 Webster] |
Platinum metals
(gcide) | Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
silver, LL. plata a thin plate of metal. See Plate, and cf.
Platina.] (Chem.)
A metallic element of atomic number 78, one of the noble
metals, classed with silver and gold as a precious metal,
occurring native or alloyed with other metals and also as the
platinum arsenide (sperrylite). It is a heavy tin-white metal
which is ductile and malleable, but very infusible (melting
point 1772[deg] C), and characterized by its resistance to
strong chemical reagents. It is used for crucibles in
laboratory operations, as a catalyst, in jewelry, for stills
for sulphuric acid, rarely for coin, and in the form of foil
and wire for many purposes. Specific gravity 21.5. Atomic
weight 195.1. Symbol Pt. Formerly called platina.
[1913 Webster +PJC]
Platinum black (Chem.), a soft, dull black powder,
consisting of finely divided metallic platinum obtained by
reduction and precipitation from its solutions. It absorbs
oxygen to a high degree, and is employed as an oxidizer.
Platinum lamp (Elec.), a kind of incandescent lamp of which
the luminous medium is platinum. See under Incandescent.
Platinum metals (Chem.), the group of metallic elements
which in their chemical and physical properties resemble
platinum. These consist of the light platinum group, viz.,
rhodium, ruthenium, and palladium, whose specific
gravities are about 12; and the heavy platinum group,
viz., osmium, iridium, and platinum, whose specific
gravities are over 21.
Platinum sponge (Chem.), metallic platinum in a gray,
porous, spongy form, obtained by reducing the double
chloride of platinum and ammonium. It absorbs oxygen,
hydrogen, and certain other gases, to a high degree, and
is employed as an agent in oxidizing.
[1913 Webster] |
Platinum sponge
(gcide) | Sponge \Sponge\ (sp[u^]nj), n. [OF. esponge, F. ['e]ponge, L.
spongia, Gr. spoggia`, spo`ggos. Cf. Fungus, Spunk.]
[Formerly written also spunge.]
1. (Zool.) Any one of numerous species of Spongiae, or
Porifera. See Illust. and Note under Spongiae.
[1913 Webster]
2. The elastic fibrous skeleton of many species of horny
Spongiae (Keratosa), used for many purposes, especially
the varieties of the genus Spongia. The most valuable
sponges are found in the Mediterranean and the Red Sea,
and on the coasts of Florida and the West Indies.
[1913 Webster]
3. Fig.: One who lives upon others; a pertinacious and
indolent dependent; a parasite; a sponger.
[1913 Webster]
4. Any spongelike substance. Specifically:
(a) Dough before it is kneaded and formed into loaves, and
after it is converted into a light, spongy mass by the
agency of the yeast or leaven.
(b) Iron from the puddling furnace, in a pasty condition.
(c) Iron ore, in masses, reduced but not melted or worked.
[1913 Webster]
5. (Gun.) A mop for cleaning the bore of a cannon after a
discharge. It consists of a cylinder of wood, covered with
sheepskin with the wool on, or cloth with a heavy looped
nap, and having a handle, or staff.
[1913 Webster]
6. (Far.) The extremity, or point, of a horseshoe, answering
to the heel.
[1913 Webster]
Bath sponge, any one of several varieties of coarse
commercial sponges, especially Spongia equina.
Cup sponge, a toilet sponge growing in a cup-shaped form.
Glass sponge. See Glass-sponge, in the Vocabulary.
Glove sponge, a variety of commercial sponge ({Spongia
officinalis}, variety tubulifera), having very fine
fibers, native of Florida, and the West Indies.
Grass sponge, any one of several varieties of coarse
commercial sponges having the surface irregularly tufted,
as Spongia graminea, and Spongia equina, variety
cerebriformis, of Florida and the West Indies.
Horse sponge, a coarse commercial sponge, especially
Spongia equina.
Platinum sponge. (Chem.) See under Platinum.
Pyrotechnical sponge, a substance made of mushrooms or
fungi, which are boiled in water, dried, and beaten, then
put in a strong lye prepared with saltpeter, and again
dried in an oven. This makes the black match, or tinder,
brought from Germany.
Sheep's-wool sponge, a fine and durable commercial sponge
(Spongia equina, variety gossypina) found in Florida and
the West Indies. The surface is covered with larger and
smaller tufts, having the oscula between them.
Sponge cake, a kind of sweet cake which is light and
spongy.
Sponge lead, or Spongy lead (Chem.), metallic lead
brought to a spongy form by reduction of lead salts, or by
compressing finely divided lead; -- used in secondary
batteries and otherwise.
Sponge tree (Bot.), a tropical leguminous tree ({Acacia
Farnesiana}), with deliciously fragrant flowers, which are
used in perfumery.
Toilet sponge, a very fine and superior variety of
Mediterranean sponge (Spongia officinalis, variety
Mediterranea); -- called also Turkish sponge.
To set a sponge (Cookery), to leaven a small mass of flour,
to be used in leavening a larger quantity.
To throw up the sponge, to give up a contest; to
acknowledge defeat; -- from a custom of the prize ring,
the person employed to sponge a pugilist between rounds
throwing his sponge in the air in token of defeat; -- now,
throw in the towel is more common, and has the same
origin and meaning. [Cant or Slang] "He was too brave a
man to throw up the sponge to fate." --Lowell.
Vegetable sponge. (Bot.) See Loof.
Velvet sponge, a fine, soft commercial sponge ({Spongia
equina}, variety meandriniformis) found in Florida and the
West Indies.
Vitreous sponge. See Glass-sponge.
Yellow sponge, a common and valuable commercial sponge
(Spongia agaricina, variety corlosia) found in Florida
and the West Indies.
[1913 Webster]Platinum \Plat"i*num\, n. [NL., fr. Sp. platina, from plata
silver, LL. plata a thin plate of metal. See Plate, and cf.
Platina.] (Chem.)
A metallic element of atomic number 78, one of the noble
metals, classed with silver and gold as a precious metal,
occurring native or alloyed with other metals and also as the
platinum arsenide (sperrylite). It is a heavy tin-white metal
which is ductile and malleable, but very infusible (melting
point 1772[deg] C), and characterized by its resistance to
strong chemical reagents. It is used for crucibles in
laboratory operations, as a catalyst, in jewelry, for stills
for sulphuric acid, rarely for coin, and in the form of foil
and wire for many purposes. Specific gravity 21.5. Atomic
weight 195.1. Symbol Pt. Formerly called platina.
[1913 Webster +PJC]
Platinum black (Chem.), a soft, dull black powder,
consisting of finely divided metallic platinum obtained by
reduction and precipitation from its solutions. It absorbs
oxygen to a high degree, and is employed as an oxidizer.
Platinum lamp (Elec.), a kind of incandescent lamp of which
the luminous medium is platinum. See under Incandescent.
Platinum metals (Chem.), the group of metallic elements
which in their chemical and physical properties resemble
platinum. These consist of the light platinum group, viz.,
rhodium, ruthenium, and palladium, whose specific
gravities are about 12; and the heavy platinum group,
viz., osmium, iridium, and platinum, whose specific
gravities are over 21.
Platinum sponge (Chem.), metallic platinum in a gray,
porous, spongy form, obtained by reducing the double
chloride of platinum and ammonium. It absorbs oxygen,
hydrogen, and certain other gases, to a high degree, and
is employed as an agent in oxidizing.
[1913 Webster] |
Spongy platinum
(gcide) | Spongy \Spon"gy\ (sp[u^]n"j[y^]), a.
1. Soft, and full of cavities; of an open, loose, pliable
texture; as, a spongy excrescence; spongy earth; spongy
cake; spongy bones.
[1913 Webster]
2. Wet; drenched; soaked and soft, like sponge; rainy.
"Spongy April." --Shak.
[1913 Webster]
3. Having the quality of imbibing fluids, like a sponge.
[1913 Webster]
Spongy lead (Chem.), sponge lead. See under Sponge.
Spongy platinum. See under Platinum.
[1913 Webster] |
platinum
(wn) | platinum
n 1: a heavy precious metallic element; grey-white and resistant
to corroding; occurs in some nickel and copper ores and is
also found native in some deposits [syn: platinum, Pt,
atomic number 78] |
platinum black
(wn) | platinum black
n 1: a fine black powder of platinum; used as a catalyst in
chemical reactions |
platinum blond
(wn) | platinum blond
n 1: a blond whose hair is a pale silvery (often artificially
colored) blond [syn: platinum blond, platinum blonde] |
platinum blonde
(wn) | platinum blonde
n 1: a blond whose hair is a pale silvery (often artificially
colored) blond [syn: platinum blond, platinum blonde] |
platinum thermometer
(wn) | platinum thermometer
n 1: thermometer that measures temperature by changes in the
resistance of a spiral of platinum wire [syn: {resistance
thermometer}, platinum thermometer] |
platinum-blonde
(wn) | platinum-blonde
adj 1: of hair color; whitish [syn: ash-blonde, {platinum-
blonde}, towheaded] |
platinum-iridium
(foldoc) | platinum-iridium
A standard, against which all others of the same
category are measured. Usage: silly.
The notion is that one of whatever it is has actually been
cast in platinum-iridium alloy and placed in the vault beside
the Standard Kilogram at the International Bureau of Weights
and Measures near Paris, as the bar defining the standard
metre once was.
"This garbage collection algorithm has been tested against
the platinum-iridium cons cell in Paris."
Compare golden.
[Jargon File]
(1997-02-20)
|
platinum-iridium
(jargon) | platinum-iridium
adj.
Standard, against which all others of the same category are measured.
Usage: silly. The notion is that one of whatever it is has actually been
cast in platinum-iridium alloy and placed in the vault beside the Standard
Kilogram at the International Bureau of Weights and Measures near Paris.
(From 1889 to 1960, the meter was defined to be the distance between two
scratches in a platinum-iridium bar kept in that same vault — this replaced
an earlier definition as 10^-7 times the distance between the North Pole
and the Equator along a meridian through Paris; unfortunately, this had
been based on an inexact value of the circumference of the Earth. From 1960
to 1984 it was defined to be 1650763.73 wavelengths of the orange-red line
of krypton-86 propagating in a vacuum. It is now defined as the length of
the path traveled by light in a vacuum in the time interval of 1/
299,792,458 of a second. The kilogram is now the only unit of measure
officially defined in terms of a unique artifact. But this will have to
change; in 2003 it was revealed that the reference kilogram has been
shedding mass over time, and is down by 50 micrograms.) “This
garbage-collection algorithm has been tested against the platinum-iridium
cons cell in Paris.” Compare golden.
|
platinum
(elements) | platinum
Symbol: Pt
Atomic number: 78
Atomic weight: 195.078
Attractive greyish-white metal. When pure, it is malleable and ductile.
Does not oxidize in air, insoluble in hydrochloric and nitric acid.
Corroded by halogens, cyanides, sulphur and alkalis. Hydrogen and
oxygen react explosively in the presence of platinum. There are six
stable isotopes and three radioisotopes, the most stable being Pt-193
with a half-life of 60 years. Platinum is used in jewelry, laboratory
equipment, electrical contacts, dentistry, and anti-pollution devices in
cars. PtCl2(NH3)2 is used to treat some forms of cancer.
Platinum-cobalt
alloys have magnetic properties. It is also used in the definition of
the Standard Hydrogen Electrode. Discovered by Antonio de Ulloa in South
America in 1735. The name comes from the Spanish word platina which
means
silver. Platinum metal is generally not a health concern due to its
unreactivity, however platinum compounds should be considered highly
toxic.
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