The helium in a balloon comes from the radioactive decay of the elements thorium and uranium. Video two in this series of 48 explores the element helium. The narrator discusses how humans use it, where it is found, how the United States...

In one of the more memorable Spangler episodes, Spangler has a large terrarium filled with sulfur-hexafluoride gas, which is six times heavier than the air we breathe! It has some amazing properties, one of which it doesn't allow...

Chemistry professor explains the role of helium in the function of the Large Hadron Collider. [4:10]

Today we are talking about the life-and death-of stars. Low mass stars live a long time, fusing all their hydrogen into helium over a trillion years. More massive stars like the Sun live shorter lives. They fuse hydrogen into helium, and...