helium
氦气,氦,氦素,氦元素
Definitions
- 1
- : an inert, gaseous element present in the sun's atmosphere and in natural gas, and also occurring as a radioactive decomposition product, used as a substitute for flammable gases in dirigible balloons. Symbol: He; atomic weight: 4.0026; atomic number: 2; density: 0.1785 grams/liter at 0°C and 760 millimeters pressure.
Examples
The team behind some of the earlier measurements is now back with a new one, this one tracking the behavior of a muon orbiting a helium nucleus.
They could change their altitude to catch different air currents by either pumping air in, or out, of a smaller balloon that was inside the larger helium vessel.
These stars were fashioned only from hydrogen and helium, the cosmos’s rawest materials.
The typical Macy’s parade balloon may use around 12,000 cubic feet of helium, while global consumption is on the order of 6 billion cubic feet per year.
The helium absorbed heat from the LEDs as it wound through the channel and expanded until it was finally released through a small nozzle.
She added in the high-pitched, over-enunciated voice, like she was alternating between sucking on helium and a bong.
Previously a big, fat tank of liquid helium was needed for the task.
So of course, Jimmy Fallon took the opportunity to ruin it by forcing Freeman to inhale helium and pitch up his voice.
Especially when the one you love has a voice like nails on a helium-soaked chalkboard.
After he inhaled sulfur hexafluoride, a compound that acts like helium, his voice got very deep.
What bug in the new helium process might account for this delay?
There was only one thing to do, there being only one other gas comparable in lightness to helium.
An atom of lithium-7 plus an atom of hydrogen-1 yields two atoms of helium-4 and plenty of energy.
He turned the dial to emergency maximum and gulped precious liters of oxygen-helium mixture.
When they opened the sample chamber, they got a blast of high-pressure helium right in the face.