Phillip Jones, age 11, of Asheville, N. C., for his question;

What is helium?

The element helium was discovered in the sun before it was known to exist on earth. At normal and high temperatures it is an invisible gas like the gases in the air. It can be chilled to a liquid state and frozen solid at minus 272 degrees Centigrade,

Helium has two properties which make it valuable as a lifting gas for balloons, blimps and dirigibles. It is much lighter than the gases of the air. What’s more, it is an aloof element. It does not blend readily with other elements nor does it catch fire easily.

At one time, hydrogen was the popular balloon lifting gas, It is the lightest of all elements and naturally has the greatest lifting power, However, it readily bursts into flame. Whenever possible, modern balloons are filled with non‑inflammable helium. Though about twice as heavy as hydrogen, helium has 92% of the lifting power of the lightest of all gases.

Helium is very rare on earth, which is why it was not found here until 90 odd years ago. There are tiny traces of it in the air and in certain minerals. But useable amounts are found only in the resources of natural gas in the United States,