She married the physicist Pierre Curie
(1859–1906) in 1895 and soon began
work on seeking radioactive el-
ements other than uranium in
pitchblende (to account for its un-
expectedly high radioactivity). By
1898 she had discovered *radium
and *polonium, although it took her
four years to purify them. In 1903
the Curies shared the Nobel Prize for
physics with Henri *Becquerel, who
had discovered radioactivity. In 1911
Marie Curie was awarded the Nobel
Prize for chemistry.Curie point (Curie temperature)
The temperature at which a ferro-
magnetic substance loses its ferro-
magnetism and becomes only
paramagnetic. For iron the Curie
point is 760°C and for nickel 356°C.
It is named after Pierre *Curie.Curie’s law The susceptibility (χ) of
a paramagnetic substance is propor-
tional to the thermodynamic temper-
ature (T), i.e. χ= C/T, where C is the
Curie constant. A modiÜcation of this
law, the Curie–Weiss law, is more
generally applicable. It states that
χ= C/(T – θ), where θis the Weiss
constant, a characteristic of the ma-
terial. The law wasÜrst proposed by
Pierre *Curie and modiÜed by an-
other French physicist, Pierre-Ernest
Weiss (1865–1940).curiumSymbol Cm. A radioactive
metallic transuranic element belong-
ing to the *actinoids; a.n. 96; mass
number of the most stable isotope
247 (half-life 1.64 × 107 years); r.d.
(calculated) 13.51; m.p. 1340± 40 °C.
There are nine known isotopes. The
element wasÜrst identiÜed by Glenn
Seaborg (1912–99) and associates in
1944 andÜrst produced by L. B.
Werner and I. Perlman in 1947 by
bombarding americium–241 with
neutrons.Curie point 156c
A
- Information from the WebElements site
cutting agent (adulterant)A sub-
stance used to dilute illegal drugs
such as heroine and cocaine. Exam-
ples includeÛour, starch, sugar, and
caffeine.
cyanamide1.An inorganic salt
containing the ion CN 2 2–. See calcium
cyanamide. 2.A colourless crys-
talline solid, H 2 NCN, made by the ac-
tion of carbon dioxide on hot
sodamide. It is a weakly acidic com-
pound (the parent acid of cyanamide
salts) that is soluble in water and
ethanol. It is hydrolysed to urea in
acidic solutions.
cyanamide process See calcium
cyanamide.cyanate See cyanic acid.cyanic acidAn unstable explosive
acid, HOCN. The compound has the
structure H–O–C≡N, and is also called
fulminic acid. Its salts and esters are
cyanates(or fulminates). The com-
pound is a volatile liquid, which
readily polymerizes. In water it hy-
drolyses to ammonia and carbon
dioxide. It is isomeric with another
acid, H–N=C=O, which is known as
isocyanic acid. Its salts and esters are
isocyanates.cyanide1.An inorganic salt con-
taining the cyanide ion CN–. Cya-
nides are extremely poisonous
because of the ability of the CN–ion
to coordinate with the iron in
haemoglobin, thereby blocking the
uptake of oxygen by the blood. 2.A
metal coordination complex formed
with cyanide ions.cyanide process A method of ex-
tracting gold by dissolving it in potas-
sium cyanide (to form the complex
ion [Au(CN) 2 ]–). The ion can be re-
duced back to gold with zinc.