LYCOS RETRIEVER 
Helium (Element): Balloons
built 264 days ago
Helium is ... used to inflate balloons and other lighter-thanair crafts, such as dirigibles (blimps). Helium does not have the lifting power of hydrogen. However, hydrogen is flammable and helium is not. At one time, people thought that dirigibles would be a popular form of transportation. But that never happened. Blimps are still used for limited purposes, such as advertising at major sports and recreational events.
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New and Feature - Helium will become to liquid when the temperature is very low. Helium is the only substance that remains liquid when the temperature is zero. People put the helium into the balloons. 4He remains liquid at zero temperature if the pressure is below 2.5 MPa.
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As explained above, inhaling Helium can change the pitch of a person's voice. However, inhaling it from a typical commercial source, such as that used to fill balloons, can be dangerous due to the number of contaminants that may be present. These could include trace amount of other gases, in addition to aerosolized lubricating oil.
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