HELIUM, THE NOBELEST GAS A little-known fact about helium, the 2nd element: Cosomologically, everything is made out of helium. As they have since the beginning of time, stars are now making helium out of unformed plasma. This helium is then used to create all the other elements, which are subsequently used to form planets, oceans, life, etc.
 
Where does helium come from?
Where can I buy helium, or helium balloons?
Why does helium make your voice squeaky?
Why is helium lighter than air?
What is the specific gravity of helium?
What are the thermal properties of helium?
Where can I find more information about the element helium?

WHERE DOES HELIUM COME FROM?
Most of the helium found on Earth is collected as a by-product of Natural Gas mining. Until the late1950's it was considered a nuisance and except for a small portion collected for industrial uses, it was allowed to escape into the atmosphere. It was then that scientists discovered that the helium that escaped was rising up to the top of the atmosphere and being blown into space by the solar winds.
 
When they realized that there was only a limited amount of helium in the Earth and that when it was gone there would be no practical way to make it, the Government began collecting the helium in giant storage tanks.
 
Today there are billions of cubic feet of compressed helium kept in the national reserves.
 
Most of the helium in the US is found in natural gas in Texas, New Mexico, Kansas, Oklahoma, Arizona, and Utah. Small amounts are found in radioactive materials meteoric iron, and mineral springs.

WHERE CAN I BUY HELIUM, OR HELIUM BALLOONS?
Check your local listings for "Helium", "Balloons", "Party Supply Stores", or "Industrial Gas Suppliers".

WHY DOES HELIUM MAKE YOUR VOICE SQUEAKY?
Helium is a non-reactive or noble gas. It does not cause any physiological or metabolic changes in your body.
 
In order to understand why your voice changes when you breathe helium, you need to understand how your voice actually works.
 
In simple terms, air moving past your vocal chords causes them to vibrate. By changing the shape of your mouth and throat, you sculpt the sound into normal speech. You change the pitch of your voice by making the space in your throat larger and smaller, and, to some extent by increasing the tension in your vocal chords.
 
Now we get to the science. In physics terms, your throat is a resonating cavity (this also applies to pipe organs, flutes, saxophones, and other wind instruments). There is a classic formula that describes these situations: velocity = frequency * wavelength. What this says is that the velocity of a sound wave in a resonating cavity is determined by the frequency and the wavelength of the sound. Now what is interesting about this is that the wavelength is determined by the shape and size of the cavity (your throat and mouth), and the velocity is determined by the density of air (which is constant).If you change the shape of the cavity you will change the wavelength which will in turn change the frequency.
 
Now the fun part. The only fixed part of the equation is the velocity. This part refers to the speed at which sound travels through air. What happens if you replace the air in your throat with helium? Well, it turns out that sound travels almost twice as fast through helium as it does through air. Ah ha! The equation tells us that the velocity has to EQUAL the frequency multiplied by the wavelength. Well, the wavelength is determined by the shape and size of the cavity. That part didn't change, so the frequency must change.
 
You experience this effect when you breathe helium. You try to talk in a 'normal' voice, but the gas in your resonating cavity has been replaced. Your brain puts your mouth and throat in the usual positions for making words(the size and shape of your resonating cavity remains fixed), and you start talking. helium has changed the velocity of sound in your throat, and as a result the frequency of the sounds that you produce are twice as high as normal.
 
I hope this helps you understand how helium affects your voice. Remember, when you breathe helium you are depriving your body of the oxygen that it needs. Always take a few breaths of air immediately after breathing helium. If you breathe it for too long, you will start to feel light-headed and dizzy. Prolonged breathing of helium could even cause suffocation!

WHY IS HELIUM LIGHTER THAN AIR?
You have asked a very good question, one that touches on the very origins of our universe and the fundamental nature of matter.
 
Helium is one of the simplest elements, it has only two electrons, two protons, and two neutrons (electrons, protons, and neutrons are some of the basic building blocks of atoms). Only hydrogen is simpler with its one electron and one proton.
 
Air is made up of many gases, but it is primarily Nitrogen, Oxygen (the part that you use when you breathe), and Carbon Dioxide (the part that you make when you exhale). Now Nitrogen has 7 electrons and 7 protons and Oxygen has 8 of each. I think you can see where we are headed here. Carbon Dioxide is a compound made from an atom of Carbon (6 electrons, 6 protons) and two Oxygen atoms, so added up that's 22 protons and 22 electrons.
 
As a general rule of thumb, the more protons and neutrons that an element has, the more dense it is. Chemists use the concept of "atomic weight" to express this. To approximate the atomic weight of an element or compound, you just add up the protons and neutrons.
 
But before you go ahead and start doing a whole bunch of math, you can already tell that helium with its 2 electrons and 2 protons is a lot lighter than any of the gases that you find in air. In fact helium is so light that when any gets into the air it rises right up to the top of the atmosphere and gets blown out into space by the solar winds.
 
Here is a question to think about: Why does ice float?

WHAT IS THE SPECIFIC GRAVITY OF HELIUM?
0.124 at 4.2144 degrees Kelvin (that's -268.93 Celsius!)

WHAT ARE THE THERMAL PROPERTIES OF HELIUM?
Melting Point: 0.95K (that's really cold!)
 
Boiling Point: 4.22K
 
Critical Temp: 5.19K (phase change from liquid to gas)