Helium is the second most abundant gas in the universe, contributing to up to 25% of the universe’s elemental mass. Consequently, it comes as no surprise that this unreactive gas plays a vital role not only in our daily lives, but in many chemical reactions that occur on an astronomical level.
Helium is considered a ‘noble gas’ due to its lack of reactivity and full valence (outer) electron shell. This chemistry is important, as it allows us to appreciate why helium is found uncombined in the universe unlike other more reactive gases like oxygen and chlorine.
Radioactive helium reactions take place in stars all the time. Nuclear fusion reactions refer to reactions where two small nuclei combine. Fusion reactions release tremendous amounts of nuclear energy. Indeed, fusion reactions can be thousands of times more powerful than the nuclear fission reactions that occur in atomic bombs.
Both helium and hydrogen are the main fuels in stars, and hence have a crucial role in maintaining our Sun and consequently all life in the universe. Additionally, helium plays an important role in astrophysics, where scientists use helium to explain many scientific and astronomical phenomena.
The phenomena of sound in space is one which can be explained through an understanding of the chemistry and importance of helium. From your own experiences, you may know that the voice of a person who has inhaled helium sounds high-pitched (and hilarious). This is because sound travels through helium three times as fast as air. Since the concentration of helium in space is far higher than its concentration on Earth, this can result in high pitched sounds being heard in space.
Consequently, contrary to popular belief, in space ‘people can hear you scream’.
In conclusion, helium plays a vital role in many aspects of our daily life. We can witness helium in fluorescent signs, hot-air balloons and many other examples. Helium performs crucial roles in space as one of the major fuel sources of stars. It is through gaining an appreciation of the chemistry associated with this important element that we can begin to understand the vast role it plays in our universe.
