'Helium' definitions:
Definition of 'helium'
From: WordNet
noun
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) [syn: helium, He, atomic number 2]
Definition of 'Helium'
From: GCIDE
- Helium \He"li*um\ (h[=e]"l[i^]*[u^]m), n. [NL., fr. Gr. "h`lios the sun.] (Chem.) 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[deg] 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. [Webster 1913 Suppl. +PJC]
Definition of 'helium'
From: GCIDE
- Noble \No"ble\, a. [Compar. Nobler; superl. Noblest.] [F. noble, fr. L. nobilis that can be or is known, well known, famous, highborn, noble, fr. noscere to know. See know.]
- 1. Possessing eminence, elevation, dignity, etc.; above whatever is low, mean, degrading, or dishonorable; magnanimous; as, a noble nature or action; a noble heart. [1913 Webster]
- Statues, with winding ivy crowned, belong To nobler poets for a nobler song. --Dryden. [1913 Webster]
- 2. Grand; stately; magnificent; splendid; as, a noble edifice. [1913 Webster]
- 3. Of exalted rank; of or pertaining to the nobility; distinguished from the masses by birth, station, or title; highborn; as, noble blood; a noble personage. [1913 Webster]
- Note: Noble is used in the formation of self-explaining compounds; as, noble-born, noble-hearted, noble-minded. [1913 Webster]
- Noble gas (Chem.), a gaseous element belonging to group VIII of the periodic table of elements, not combining with other elements under normal reaction conditions; specifically, helium, neon, argon, krypton, xenon, or radon; also called inert gas.
- Noble metals (Chem.), silver, gold, and platinum; -- so called from their resistance to oxidation by air and to dissolution by acids. Copper, mercury, aluminium, palladium, rhodium, iridium, and osmium are sometimes included. [1913 Webster]
- Syn: Honorable; worthy; dignified; elevated; exalted; superior; sublime; great; eminent; illustrious; renowned; stately; splendid; magnificent; grand; magnanimous; generous; liberal; free. [1913 Webster]
Definition of 'Helium'
From: Elements
- Symbol: He
- Atomic number: 2
- Atomic weight: 4.0026
- Colourless, odourless gaseous nonmetallic element. Belongs to group 18 of the periodic table. Lowest boiling point of all elements and can only be solidified under pressure. Chemically inert, no known compounds. Discovered in the solar spectrum in 1868 by Lockyer.