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India

Subject: History

The world's largest democracy has a rich and diverse culture. Now, it is also achieving more rapid economic growth India's vast territory can be divided into three main regions ...

thorium

thorium  

Symbol Th. A grey radioactive metallic element belonging to the actinoids; a.n. 90; r.a.m. 232.038; r.d. 11.5–11.9 (17°C); m.p. 1740–1760°C; b.p. 4780–4800°C. It occurs in monazite sand in Brazil, ...
emerald

emerald   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
58 words

...The green gem variety of beryl : one of the most highly prized gemstones. The finest specimens occur in the Muzo mines, Colombia. Other occurrences include the Ural Mountains, the Transvaal in South Africa, and Kaligunan in India. Emeralds can also be successfully synthesized. The green colour of emerald is due to small amounts of chromium...

magnesite

magnesite   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
62 words

..., MgCO 3 , crystallizing in the trigonal system. It is formed as a replacement mineral of magnesium-rich rocks when carbon dioxide is available. Magnesite is mined both as an ore for magnesium and as a source of magnesium carbonate. It occurs in Austria, USA, Greece, Norway, India, Australia, and South...

diamond

diamond   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
124 words
Illustration(s):
1

...volcanic pipes of kimberlite; the most important deposits are in South Africa but others are found in Tanzania, the USA, Russia, and Australia. Diamonds also occur in river deposits that have been derived from weathered kimberlite, notably in Brazil, Zaïre, Sierra Leone, and India. Industrial diamonds are increasingly being produced synthetically....

biogas

biogas   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
114 words

...obligate anaerobes produce methane, the main component of biogas, which can be collected and used as an energy source for domestic processes, such as heating, cooking, and lighting. The production of biogas is carried out in special digesters , which are widely used in China and India. As well as providing a source of fuel, these systems also enable sewage, which contains pathogenic bacteria, to be digested, thereby removing the danger to humans that could otherwise result from untreated domestic and agricultural...

thorium

thorium   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
126 words

...Symbol Th. A grey radioactive metallic element belonging to the actinoids ; a.n. 90; r.a.m. 232.038; r.d. 11.5–11.9 (17°C); m.p. 1740–1760°C; b.p. 4780–4800°C. It occurs in monazite sand in Brazil, India, and USA. The isotopes of thorium have mass numbers from 223 to 234 inclusive; the most stable isotope, thorium-232, has a half-life of 1.39×10 10 years. It has an oxidation state of (+4) and its chemistry resembles that of the other actinoids. It can be used as a nuclear fuel for breeder reactors as thorium‐232 captures slow neutrons to breed...

coal

coal   Quick reference

A Dictionary of Chemistry (7 ed.)

Reference type:
Subject Reference
Current Version:
2016
Subject:
Science and technology, Chemistry
Length:
295 words

...formed during the Carboniferous and Permian periods. More recent periods of coal formation occurred during the early Jurassic and Tertiary periods. Coal deposits occur in all the major continents; the leading producers include the USA, China, Ukraine, Poland, UK, South Africa, India, Australia, and Germany. Coal is used as a fuel and in the chemical industry; by-products include coke and coal...

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