First of all, there isn't much choice.
To get the airship to lift, one has to use a gas that's lighter than air. Only two do that well enough to be useful, hydrogen and helium.
Hydrogen is lighter and cheaper, but horribly flammable.
Helium is more expensive, provide less lift, but is entirely non flammable.
Yes. Helium isn't flammable, which makes it the safer option.
An airship uses helium which weighs less than air, and it cancels out the weight of the airship. Hydrogen weighs even less than helium, but it is combustible, so helium is preferred for use in airships.
In their early history, buoyant airships (zepellins, blimps) were filled with hydrogen, a highly flammable gas. Since the Hindenburg disaster, hydrogen has been supplanted by helium, a much more expensive material, but one that is inert and hence much safer.
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Today's blimps are not filled with flammable hydrogen gas like Hindenburg was, but normally the non-flammable helium.
Helium has replace hydrogen in airships
helium, mostly
Yes. Helium isn't flammable, which makes it the safer option.
Airships are usually the shape of a oval. They look like blimps. Airships are usually filled with helium to keep them afloat.
Helium is typically used to fill airships and balloons due to its low density, which allows them to float in the air.
Hydrogen and helium are two elements that are kinda-sorta interchangeable in airships.
Hydrogen (explosive), Helium (non-explosive).
The gas that helium replaced was Hydrogen
Helium is inert. Will not burn like hydrogen does so well.
helium is used to cool superconducting magnets in mri scanners as helium is lighter then air airships use them as gasses
Helium is a lighter gas than oxygen, ever seen balloons filled with helium? They rise upwards with heat due to a lesser amount of particles. If we used oxygen, the airships wouldn't get off the ground!
Hydrogen and helium gases are commonly used in airships for lift. Helium is safer than hydrogen due to its non-flammable nature, although it is less buoyant.