August 18 – Celebrate the Discovery of Helium!

nPostednon August 18, 2015

nOnnthis date in 1868, French astronomer Pierre Janssen discoverednhelium.

nItnwas the first time that a chemical element had been discoverednsomewhere else in the universe before it was discovered here onnEarth. Helium was discovered in the Sun’s spectrum, and so it isnnamed after the Greek sun god, Helios.

nDuringnan eclipse on this date in 1868, Janssen used a spectroscope andnobserved bright lines in the spectrum of the Sun’s chromospheren(which is the middle layer of the three main layers in the Sun’snatmosphere). Those bright lines showed that the chromosphere was gas,nJanssen said. There was a bright yellow line that didn’t correspondnto any known element (and of course, this was the helium line), butnJanssen didn’t actually write about that. Instead, he realized thatnthe Sun’s chromospheric spectrum could be observed even without anneclipse, and THAT innovation is what he spent his time and effort on.

nLaternthat same year, Joseph Lockyer of England set up a spectroscope to donwhat Janssen had pointed out could be done – to observe the Sun’snchromosphere without waiting for an eclipse. And it was he whoncommented on that bright yellow line, and it was he and a chemistnnamed Edward Frankland who named the element.

MeetnHelium

nHeliumnis the second lightest element in the universe, with an atomic numbernof 2.
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nOnly hydrogen (atomic number 1) is lighter.

nHeliumnis also the second most common element in the universe. (Again,nhydrogen is the most common.)

nHydrogennis colorless, odorless, tasteless, non-toxic, inert. It is a noblengas. Inert and noble gas basically mean the same thingn– helium doesn’t react with other elements. That’s because it’snouter shell of electrons is full up – it doesn’t have an extranelectron or two it wants to get rid of, and it’s not lacking annelectron or two to make a full shell. It’s “just right,” just asnit is!
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nGetn more info on helium at Ducksters.

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nHaven you ever tried talking on helium? The gas is so light that ourn voices get much higher. Take a listen to one,n two,n or three videos!

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IMPORTANT NOTE: Because helium is inert, it doesn’t react with our bodies, so it is pretty safe to “talk on helium” once in a very long while BUT there are three big “buts.”

n1. Be sure to take some regular breaths in between so you are getting plenty of oxygen!

n2. It can be quite dangerous to breathe straight from the tank. Be sure to put helium in a balloon, and then breathe it in from the balloon. Again, do NOT breathe straight from the tank.

n3. Hold onto the balloon! Don’t suck in the thin rubber along with the helium!