FORMATION corresponding to a distinct POTENTIAL-
ENERGY minimum), arising from restricted rotation
about one single bond.
rotational energy Energy due to the tumbling
motion of the molecule.
rotational spectrum Molecular spectrum resulting
from transitions between rotational levels of a
molecule.
rubisco See RIBULOSE-1,5-BISPHOSPHATE CARBOXY-
LASE/OXYGENASE.
rubredoxin An IRON-SULFUR PROTEINwithout ACID-
LABILE SULFUR, in which an iron center is COORDI-
NATED by four sulfur-containing LIGANDs, usually
cysteine. The function, where known, is as an electron
carrier.
rubrerythrin A protein assumed to contain both a
RUBREDOXIN-like iron center and a HEMERYTHRIN-like
DINUCLEARiron center.
ruby A red gemstone composed of corundum (Al 2 O 3 )
containing a small amount of chromium. Because of its
radiative properties, ruby crystals were used in some of
the first LASERs (ruby lasers, whose emissions were in
the red spectrum).
rusticyanin An ELECTRON-TRANSFER PROTEIN, con-
taining a TYPE 1 COPPERsite, from the periplasm of the
iron-oxidizing bacterium Thiobacillus ferrooxidans.
Rutherford, Ernest (1871–1937) British Physicist
Ernest Rutherford was born on August 30, 1871, in
Nelson, New Zealand, to James Rutherford, a Scottish
wheelwright who emigrated to New Zealand in 1842.
His mother, Martha Thompson, an English
schoolteacher, followed in 1855.
Educated in government schools, Rutherford
entered Nelson College at the age of 15, and in 1889
he was awarded a university scholarship to the Univer-
sity of New Zealand, Wellington, entering Canterbury
College. He received a M.A. in 1893 with a double first
in mathematics and physical science, and a bachelors of
science the following year. In 1895 after receiving a
scholarship, he entered Trinity College, Cambridge, as
a research student at the Cavendish Laboratory under
J. J. Thomson.
In 1892 he was awarded a B.A. research degree
and the Coutts-Trotter Studentship of Trinity College,
and the following year he accepted the Macdonald
chair of physics at McGill University, Montreal.
In 1900 Rutherford married Mary Newton, and
they had one daughter.
In 1907 he returned to England to become the
Langworthy professor of physics at the University of
Manchester, and in 1919 became the Cavendish profes-
sor of physics at Cambridge and chairman of the advi-
sory council, H. M. Government, Department of
Scientific and Industrial Research; professor of natural
philosophy, Royal Institution, London; and director of
the Royal Society Mond Laboratory, Cambridge.
Rutherford’s work has made him known as the
father of nuclear physics with his research on radioac-
tivity (alpha and beta particles and protons, which he
named), and he was the first to describe the concepts of
half-life and decay constant. He showed that elements
such as uranium transmute (become different elements)
through radioactive decay, and he was the first to
observe nuclear reactions (split the atom in 1917). In
1908 he received the Nobel Prize in chemistry “for his
investigations into the disintegration of the elements,
and the chemistry of radioactive substances.” He was
president of the Royal Society (1926–30) and of the
Institute of Physics (1931–33) and was decorated with
the Order of Merit (1925). He became Lord Ruther-
ford in 1931.
He died in Cambridge on October 19, 1937, and
his ashes were buried in Westminster Abbey, next to
Lord Kelvin and just west of Sir Isaac Newton’s tomb.Rydberg series A Rydberg state is a state of an atom
or molecule in which one of the electrons has been
excited to a high principal quantum number orbital. A
Rydberg series is the set of bound states of the excited
electron for a given set of excited electron angular
momentum quantum numbers and ion core state.240 rotational energy