The gas that helium replaced was Hydrogen
Yes. Helium isn't flammable, which makes it the safer option.
Helium is inert. Will not burn like hydrogen does so well.
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.
Because Helium is inflammable and the safer choice.
Modern airships use Helium for lift which is non-combustible whereas in the past airships such as the Hindenburg used Hydrogen for lift which is highly combustible. In addition, modern airships take advantage of new alloys and polymers which give them a much stronger airframe.
Hydrogen was one of the earliest gases to be used for inflatable flying balloons, but following the Hindenberg disaster helium is now used, as it is chemically inert.
Helium is lighter than air, providing lift for airships. Carbon dioxide is denser than air, so it would not provide the necessary buoyancy. Additionally, helium is non-combustible, making it a safer choice for aviation.
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.
because hydrogen used to be in those airships and since hydrogen is flammable it was very dangerous
Hydrogen gas is highly flammable and poses a significant safety risk. Therefore, helium gas is commonly used in airships today as it is non-flammable and safer. Additionally, helium has a higher lifting capacity compared to hydrogen, which allows for better control and stability of the airship.
Hydrogen is highly flammable, posing a significant safety risk for airships. This was highlighted by disasters such as the Hindenburg crash in 1937. As a result, the use of hydrogen in airships was phased out in favor of safer alternatives like helium.
Helium, but there are more limited supplies of it. At the time of the Hindenburg, the US was the sole source with all of it coming from Texas oil fields mixed in with the natural gas. It was there because of the combination of deep Uranium Ore deposits and Salt Domes, Uranium decay alphas captured electrons becoming Helium then got caught in the salt domes with the natural gas on top of the oil. The US refused to sell Helium, a strategic resource to Nazi Germany. Helium is a Nobel Gas thus inert, Hydrogen ignites and burns easily.