THE PERIODIC TABLE
ELEMENT NAME: Helium
SYMBOL: He
ATOMIC NUMBER: 2
CLASSIFICATION: Noble Gas
YEAR OF DISCOVERY: 1868
ETYMOLOGY: Named after the Greek word for Sun, Helios, as it was first detected in the corona of the sun.
DISCOVERY: The first evidence of helium was observed on August 18, 1868, as a bright yellow line in the emmision spectrum of the Sun's atmosphere. French astronomer Jules Janssen saw the line at Guntur, India, during a total solar eclipse. This line was initially assumed to be sodium. The same year, on October 20, English astronomer Norman Lockyer noticed the yellow line in the solar spectrum and concluded that it was created by an element in the Sun that hadn't been discovered to humans. Lockyer gave the element its name from the Greek term helios, meaning sun. The suffix "-ium" is peculiar because it usually refers to metallic elements alone. Since Lockyer was an astronomer, it's possible that he was unaware of chemical conventions or that it was originally believed to be metallic. Without this ending, it would probably have been named "heon" or "helion".
USES:
- About 32% of the world's helium production in 2014 was utilized for cryogenic purposes, the majority of which included cooling the superconducting magnets in NMR spectrometers and medical MRI scanners. 96 metric tons of liquid helium are used in the Large Hadron Collider at CERN to keep the temperature at 1.9 K (−271.25 °C).
- Because helium is inert, it is employed as a protective gas in the growth of silicon and germanium crystals, and in the manufacturing of titanium and zirconium.
- Leak detection is one industrial application of helium. As helium diffuses through solids three times more quickly than air, it is used as a tracer gas in high-vacuum and high-pressure containers to find leaks. The tested object is placed in a chamber, which is then filled with helium. The helium that escapes through the leaks is detected by a sensitive device (a helium mass spectrometer)
- Because it is lighter than air, airships and balloons are inflated with helium for lift. While hydrogen gas is more buoyant, helium has the advantage of being non-flammable.
- Barcode readers and laser pointers were among the many useful uses for helium-neon lasers, a type of low-power gas laser that produced a red beam, before they were nearly completely superseded by less expensive diode lasers.
FUN FACT: Laser is actually an acronym! It stands for "light amplification by stimulated emission of radiation". (I learnt this fact from a Sonic the Hedgehog video lol (link))
Invisible lasers that operate in microwave frequencies (masers) also exist, and actually predate the laser.
OTHER INFORMATION:
- Although it is relatively rare on Earth, helium is the second most abundant element in the known universe.
- Of all the chemical elements in the observable universe, the melting point and boiling point of helium are the lowest.
- Most of the helium in our universe was formed in the about three minutes that followed the Big Bang.
- The reason why your voice becomes sqeaky after inhaling helium is that vocal cord vibration is faster when the gas around the cords has a lower density.