Ted Compton, age 10, of Eureka, Calif., for his question:

WHEN WAS HELIUM DISCOVERED?

Helium is a lightweight gas and chemical element. It is called an inert gas or noble gas because it does not combine with other elements.

Helium was first found on the earth in 1895. A Scottish chemist named Sir William Ramsay and the Swedish chemists Nils Langlet and Per Theodor Cleve found it in the mineral clevite.

Earlier, in 1868, evidence of helium in the sun was discovered by an English astronomer named Sir Joseph Lockyer. Lockyer found the evidence while studying the sun's light during an eclipse. He invented  the name from the Greek word helios, meaning sun.

About 700 million cubic feet of helium are used in the United States each year. The government uses about three fourths of this amount with most being used in rockets.