Deuterium
Deuterium (symbol 2H) is a stable isotope of hydrogen with a natural abundance of one part in 7000 of hydrogen. The nucleus of deuterium (called a deuteron) has one proton and one neutron, whereas a normal hydrogen nucleus just has one proton. Deuterium is also called heavy hydrogen. While it isn't an element in its own right, it is often given the symbol D. It occurs naturally as deuterium gas, D2 or 2H2.
Deuterium was discovered in 1931 by Harold Clayton Urey[?], a chemist at Columbia University, for which he earned the Nobel prize in chemistry in 1934.
It is useful in nuclear fusion reactions, as is tritium, because of the larger rate of reaction (or cross section) and high energy yield of the D-T reaction.
Deuterium can replace the normal hydrogen in water molecules to form heavy water (D2O), which was a source of some concern during World War II, as Germany was known to be conducting experiments using heavy water as a nuclear reactor moderator, which might allow them to produce plutonium for an atomic bomb. This led to an important Allied special forces operation to destroy a deuterium production facility in Norway.
Deuterium is frequently used in chemistry and biochemistry as a tracer molecule to study reaction pathways because chemically it behaves identically to ordinary hydrogen, but it can be distinguished from ordinary hydrogen by its mass. Also, because of its greater mass, chemical reactions involving deuterium tend to occur at a slower rate than the corresponding reactions involving ordinary hydrogen.
It has been suggested that deuterium water (heavy water) should be considered toxic because if consumed in isolation it would displace light water and disturb the rate of biochemical reactions in the body. See heavy water for a discussion of this.
The existence of deuterium in stars is one of the arguments in favour of the big bang theory over the steady state[?] theory. Stellar fusion destroys deuterium and there are no known processes other than the big bang itself which produce deuterium.
Canada is the world's leading producer of deuterium as it is needed for the operation of the CANDU reactor.
Data
- density: 0.180 kg.m-3 at STP.
- atomic weight: 2.01363.
have been waiting a long, long time to see you. So many thoughts crowd
have delivered it--so listen now."
Hosea nodded assent and, after drinking the healing potion handed to him,
Ephraimite. Thy name.html">name.html">name is Hosea, 'the Help,' and the Lord our God hath
command.html">command, thou shalt be called Joshua,--[Jehoshua, he who helps Jehova]--
who is the God of thy fathers likewise, bids thee be the sword and
thine arm that He may smite the foe."
Ephraim had begun in a low voice, but gradually his tones grew more
stillness of the night.
Thus had Miriam uttered them, laying her hands on the lad's head and
while repeating them he had felt as though some secret power were
from the lips of the prophetess. Then, with a sigh of relief, he turned
again."
The youth obeyed, but this time he repeated the words in a low, careless
burning head, extinguished the light, and flung more fuel on the
as if in a dream. At last he sat down, and propping his elbows on his
and anon into the flames.
Who was this God who summoned him through Miriam's lips to be, under His
name was everything "Honor to the name of Pharaoh," not "Honor to
Joshua, the behest involved casting aside his former self, and becoming a
less a thing than the command to transform himself from the Egyptian his
to act and feel like an Israelite! Miriam's summons called him back to
his father's expectations. Instead of the Egyptian troops whom he must
battle! This was the meaning of her bidding, and when the noble virgin
her lips, it was no idle boast, she was really obeying the will of the
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