Metallic hydrogen

Metallic hydrogen is a phase of hydrogen in which it behaves as an electrical conductor. This phase was predicted theoretically in 1935 but has yet to be unambiguously observed, but possibly some new phases of solid hydrogen have been observed under static conditions and electrical insulator to conductor transitions have been reported associated with an increase in optical reflectivity in dense liquid deuterium which is consistent with metallic behaviour. At high pressure, on the order of hundreds of gigapascals, hydrogen might exist as a liquid rather than a solid. Liquid and solid metallic hydrogen is thought to be present in large amounts in the gravitationally compressed interiors of Jupiter, Saturn, and in some extrasolar planets.

Theoretical predictions

Metallization of hydrogen under pressure

Though at the top of the alkali metal column in the periodic table, hydrogen is not, under ordinary conditions, an alkali metal. In 1935 physicists Eugene Wigner and Hillard Bell Huntington predicted that under an immense pressure of around 7010250000000000000♠25 GPa (7010253312500000000♠250000 atm or 7010241316505260892♠3500000 psi), hydrogen atoms would display metallic properties, losing hold over their electrons. Since then, metallic hydrogen has been described as "the holy grail of high-pressure physics".

Harvard University

Harvard University is a private Ivy League research university in Cambridge, Massachusetts, established 1636, whose history, influence and wealth have made it one of the most prestigious universities in the world.

Established originally by the Massachusetts legislature and soon thereafter named for John Harvard (its first benefactor), Harvard is the United States' oldest institution of higher learning, and the Harvard Corporation (formally, the President and Fellows of Harvard College) is its first chartered corporation. Although never formally affiliated with any denomination, the early College primarily trained Congregationalist and Unitarian clergy. Its curriculum and student body were gradually secularized during the 18th century, and by the 19th century Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure (1869–1909) transformed the college and affiliated professional schools into a modern research university; Harvard was a founding member of the Association of American Universities in 1900.James Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College.

Hydrogen

Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 7000100794000000000♠1.00794 u, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol ¹H), has one proton and no neutrons.

The universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H₂. Since hydrogen readily forms covalent compounds with most non-metallic elements, most of the hydrogen on Earth exists in molecular forms such as in the form of water or organic compounds. Hydrogen plays a particularly important role in acid–base reactions as many acid-base reactions involve the exchange of protons between soluble molecules. In ionic compounds, hydrogen can take the form of a negative charge (i.e., anion) when it is known as a hydride, or as a positively charged (i.e., cation) species denoted by the symbol H⁺. The hydrogen cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds are always more complex species than that would suggest. As the only neutral atom for which the Schrödinger equation can be solved analytically, study of the energetics and bonding of the hydrogen atom has played a key role in the development of quantum mechanics.

Ranga Dias

Wadugamudalige Joseph Maurice Ranga Dias (born August 14, 1979, Kandy) is a Sri Lankan cricketer. He plays first class cricket for the Tamil Union Cricket and Athletic Club and also represents Sri Lanka A. Debuting in 1999/00, Dias is a right-arm fast-medium bowler.

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