An inert, monoatomic, gaseous element occurring in the atmosphere of the sun and stars, and in small quantities in the earth's atmosphere, in several minerals and in certain mineral waters. It is obtained from natural gas in industrial quantities. Symbol, He; atomic number 2; at. wt., 4.0026 (C=12.011). Helium was first detected spectroscopically in the sun by Lockyer in 1868; it was first prepared by Ramsay in 1895. Helium has a density of 1.98 compared with hydrogen, and is more difficult to liquefy than the latter. Chemically, it is an inert noble gas, belonging to the argon group, and cannot be made to form compounds. The helium nucleus is the charged particle which constitutes alpha rays, and helium is therefore formed as a decomposition product of certain radioactive substances such as radium. The normal helium nucleus has two protons and two neutrons, but an isotope with only one neutron is also observed in atmospheric helium at an abundance of 0.013 %. Liquid helium has a boiling point of -268.9° C at atmospheric pressure, and is used for maintaining very low temperatures, both in laboratory experimentation and in commercial applications to maintain superconductivity in low-temperature superconducting devices. Gaseous helium at normal temperatures is used for buoyancy in blimps, dirigibles, and high-altitude balloons, and also for amusement in party balloons.
atom consisting of two protons and two electrons.
An inert gas that is lighter than air (either Nike AIR or normal breathing air). Predominately sourced from natural gas wells in Texas. Converse introduced a basketball shoe with helium in November 1999, followed by a helium-cushioned skate shoe in 2000.
a rare gas or cryogenic liquid that is inert, colorless, odorless, and tasteless. Helium is used as an inert gas in systems for purging, blanketing, and pressurizing and as a carrier gas. It also is used as a substitute for argon in many plasma and annealing processes.
An inert, monoatomic, gaseous element occurring in the atmosphere of the sun and stars, and in small quantities in the earth's atmosphere. Helium is by-product of the thermonuclear fusion of hydrogen occuring in the Sun.
An inert gas. A colorless, monatomic element which is found to occur in dry air to the extent of only 0.000524 percent by volume. Helium is very light, having a molecular weight of only 4.003 and specific gravity referred to air of 0.138. Because helium is non-inflammable and has a lifting power 92 percent of that of hydrogen, it is widely used as the inflation gas for meteorological balloons.
The gas made from hydrogen in the core of stars by nucleosynthesis. Each atom of helium contains two protons.
Helium is one of the lightest gases in nature, and is the second most common element in the universe. Our supply of helium comes from natural gas deposits and is a limited resource.
A colorless, nontoxic, noncombustible gas. Uses include welding, leak detection, chromatography, geological dating, diving. Hazard: Simple asphyxiant.
The second element in the periodic table, has 2 protons, 2 neutrons, and is a noble gas. It has an atomic mass of 4.00260 amu, and is inert. Helium was discovered in 1825 by Sir W. Ramsay of England, and N. Lenget and P.T. Cleve of Sweden. Helium melts at -272.2 degrees Celsius, and boils at -268.934 degrees Celsius. Helium has a density of 0.1785 g/L at STP (20 degrees C, 1 atm)
He. Element 2, atomic weight 4.0026. A colorless, odorless, inert gas, first discovered in the emission spectrum of the sun in 1868.
An inert colourless gas, one-sevcnth of the weight of air. It is preferable to hydrogen for use in airships because it is non-inflammable. Unfortunately it is very costly and is only found in workable quantities in North America, and it is twice as heavy as hydrogen.
One of the lightest elements, second only to hydrogen. Helium is one of the harmless by-products of nuclear fusion. It is also used in balloons and will make your voice squeaky if you inhale it. Don't inhale too much, though. Your body needs a little oxygen, too. - WebElements: Helium
a gaseous element, with an atomic number of 2. Signified as He.
An element which, after hydrogen, is the second-lightest and second-most-abundant in the Universe.
a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
a very light nonflammable gaseous chemical element occurring in various natural gases.
a gas that's lighter-than-air.
A light, colorless, nonflammable gaseous element found especially in conjunction with natural gas and used mainly in cryogenic applications, medical technology, military uses and welding.
the second lightest element; consists of two protons, and usually two neutrons and two electrons; about 8 percent of the atoms in the universe are helium
A colorless, odorless gas. It is the 2nd most abundant element in the universe.
The second lightest and second most abundant element. The typical helium atom consists of a nucleus of two protons and two neutrons surrounded by two electrons. Helium was first discovered in our Sun. Roughly 25 percent of our Sun is helium.
A colorless, odorless, inert gas, specific gravity 0.1368, found in some natural gas.
Helium: Monatomic noble gas. Most inert element, atomic number 2. Use as a plasma gas in plasma spraying.
a colorless, odorless, tasteless gas (Helium becomes a liquid near absolute zero. Liquid helium is used to cool Jefferson Lab's accelerator components.)
second lightest gas; does not cause problems of narcosis seen with nitrogen, and is therefore used for very deep diving.
The second lightest chemical element, after hydrogen. A helium atom consists of two protons, two neutrons, and two electrons. It is a gas at room temperatures and is used for example to float balloons.
(Symbol He.) Lightest of the noble gases, atomic number 2, atomic weight 4.003. It has an atomic mass of 4 (2 protons and 2 neutrons) and is a colorless, monatomic element. It is the sixth most abundant gas in dry air. Helium is very light, having a specific gravity referred to air of 0.138. This element is unique in that its existence on the sun was recognized prior to its discovery on the earth. Spectroscopic discovery in 1868 by Janssen in the solar spectrum was followed by terrestrial detection in 1889 and chemical isolation in 1894 by Ramsay. Because helium is not flammable and has a lifting power 92% of that of hydrogen, it is widely used as the inflation gas for lighter-than-air craft and for meteorological balloons. Helium nuclei are identical to radioactive alpha particles and helium is formed as a product of radioactive decay of certain elements, particularly the uranium group. Consequently, helium is often associated with deep deposits of fossil oil or gas and is released on mining.
Helium is an element with the atomic number 2. It has two protons and two neutrons in its nucleus which is orbited by two electrons. It is the second most abundant element in the universe. It is created from hydrogen atoms in the process of nuclear fusion that occurs within stars. The Sun is about 25% Helium. Helium was named after the Sun (called "Helios" in Greek) because it was first discovered on the Sun by Jules Janssen in 1868. Helium is plentiful on the Sun and rare on Earth.
|- | 3He || 0.000137%* || colspan="4" | He is stable with 1 neutron
