A sample of the element
The lightest chemical element (symbol H) with an atomic number of 1 and atomic weight of 1.00794
An atom of the element
Molecular hydrogen (H2), a colourless, odourless and flammable gas at room temperature
A colorless and odorless gaseous element The lightest and apparently the most abundant chemical element in the universe However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0 00005 percent by volume of dry air Hydrogen has a molecular weight of 2 0160 and specific gravity referred to air of 0 0695 At one time hydrogen was the commonly used inflation gas for meteorological balloons, but because of its dangerous combustibility, it has been largely replaced by helium
A colourless, odourless, tasteless, flammable gas, it occurs as the diatomic molecule H2. Its atom consists of one proton (the nucleus) and one electron; the isotopes deuterium and tritium have an additional one and two nuclear neutrons, respectively. Though only the ninth most abundant element on Earth, it represents about 75% of all matter in the universe. Hydrogen was formerly used to fill airships; nonflammable helium has replaced it. It is used to synthesize ammonia, ethanol, aniline, and methanol; to treat petroleum fuels; as a reducing agent (see reduction) and to supply a reducing atmosphere; to make hydrogen chloride (see hydrochloric acid) and hydrogen bromide; and in hydrogenation (e.g., of fats). Liquid hydrogen (boiling point -423 °F [-252.8 °C]) is used in scientific and commercial applications to produce extremely low temperatures and as a rocket propellant and a fuel for fuel cells. Combustion of hydrogen with oxygen gives water as the sole product. The properties of most acids, especially in water solutions, arise from the hydrogen ion (H^+, also referred to as the hydronium ion, H3O^+, the form in which H^+ is found in a water environment). See also hydride; hydrocarbon. heavy hydrogen hydrogen bomb hydrogen bonding
An inert gas, and lightest of all the elements, has been used in experimental diving situations
An in flammable, colorless, odorless, gaseous chemical element the lightest of all known substances
The lightest of the chemical elements, it forms organic compounds with carbon The amount of dissolved hydrogen in groundwater can also indicate the redox state and pH of the local environment
An element consisting of one electron and one proton Hydrogen is the lightest of the elements and is the building block of the universe Stars form from massive clouds of hydrogen gas
the lightest element in the universe, composed of one proton and one electron
It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad
{i} (H) colorless odorless gas (lightest of the known elements)
a chemical element Two atoms of hydrogen are found in every water molecule (H2O)
The simpliest and lightest of the elements, that is normally a colorles, ordorless highly flammable diatomic gas, that occurs in the free state only sparely on the earth and in its atmosphere though abundantly in the sun