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An inflatable laser maze. This is a non-comprehensive list of inflatable manufactured goods, as no such list could ever completely contain all items that regularly change.An inflatable [1] is an object that can typically be inflated with a gas, including air, hydrogen, helium and nitrogen.
Some types also use steerable propellers or ducted fans. Operating in a state heavier than air avoids the need to dump ballast at lift-off and also avoids the need to lose costly helium lifting gas on landing (most of the Zeppelins achieved lift with very inexpensive hydrogen, which could be vented without concern to decrease altitude).
Helium is inert - it does not react with other substances or combust - and its atomic number is 2, making it the second lightest element after hydrogen. Rockets need to achieve specific speeds and ...
Decorators may use helium balloons to create balloon sculptures. Usually the round shape of the balloon restricts these to simple arches or walls, but on occasion more ambitious "sculptures" have been attempted. It is also common to use balloons as table decorations for celebratory events. Balloons can sometimes be modeled to form shapes of ...
A major advantage is that this gas is noncombustible. But the use of helium has some disadvantages, too: The diffusion issue shared with hydrogen (though, as helium's molecular radius (138 pm) is smaller, it diffuses through more materials than hydrogen [4]). Helium is expensive. Although abundant in the universe, helium is very scarce on Earth.
Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures.Liquid helium may show superfluidity.. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (−452.20 °F; 4.15 K).
Liquid hydrogen can be stored and transported without boil-off, by using helium as a cooling refrigerant, since helium has an even lower boiling point than hydrogen. Hydrogen is lost via venting to the atmosphere only after it is loaded onto a launch vehicle, where there is no refrigeration.
Helium is the smallest and the lightest noble gas and one of the most unreactive elements, so it was commonly considered that helium compounds cannot exist at all, or at least under normal conditions. [1] Helium's first ionization energy of 24.57 eV is the highest of any element. [2]