Of these six isotopes, only those with mass numbers of three (helium-3, or He) are stable; all the others are radioactive, decaying very rapidly into other substances.The helium that is present on Earth is not a primordial component but has been generated by radioactive decay.The nucleus of every helium atom contains two protons, but, as is the case with all elements, isotopes of helium exist.The known isotopes of helium contain from one to six neutrons, so their mass numbers range from three to eight.
Helium-4 is by far the most plentiful of the stable isotopes: helium-4 atoms outnumber those of helium-3 about 700,000:1 in atmospheric helium and about 7,000,000:1 in certain helium-bearing minerals. The normal liquid form is called helium I and exists at temperatures from its boiling point of 4.21 K (−268.9 °C) down to about 2.18 K (−271 °C).
Put the Stencil on a canvas and spray paint over it and then peel it off and have your design on the canvas. All our decals are machine cut from high quality, self-adhesive vinyl. Each order comes with application instructions or you can watch our youtube videos. Customized die-cut Decals and Lettering for your car or truck window.
We will have a plotter cut it out the design on painter masking sheets. Sometimes people use laptop decals to differentiate from others.
Below 2.18 K, thermal conductivity of helium-4 becomes more than 1,000 times greater than that of copper.
This liquid form is called helium II to distinguish it from normal liquid helium I.