The Properties and Uses of Helium

The video discusses the discovery of helium during a solar eclipse in 1868 by Pierre Janssen and Norman Lockyer. Helium is a noble gas, the second most abundant element in the universe, formed during the Big Bang and through nuclear fusion in stars. On Earth, helium is sourced from natural gas fields and radioactive decay. It is used in balloons, medical cryogenics, and airships due to its low density and non-flammability. However, helium poses safety risks, such as suffocation and lung damage if inhaled improperly.

Who first noticed the yellow line in the sun's spectrum during a solar eclipse?

• Albert Einstein

• Isaac Newton

• Sir Norman Lockyer

• Pierre Julius Cesar Janssen

What group of elements does helium belong to?

• Alkali metals

• Transition metals

• Noble gases

• Halogens

How is helium primarily formed in the universe?

• Through volcanic activity

• By nuclear fusion of hydrogen in stars

• By chemical reactions in the atmosphere

• Through the decay of carbon

Which of the following is a common use of helium?

• Cleaning agent

• Cooking gas

• Inflating balloons

• Fuel for cars

Why is helium preferred over hydrogen for inflating airships?

• Helium is more buoyant

• Helium is non-flammable

• Helium is cheaper

• Helium is heavier