French Revolution Timeline May 5, 1789 A meeting of the Estates-General is called by Louis XVI in Versailles to discuss and approve a new tax plan. June 17, 1789 Three Poitevin cures decide to join the Third Estate, leaving the Chambers of the Clergy.
Helium is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among all the elements.
Helium has a very low viscosity, a high diffusion coefficient, and the smallest atom of any element. These characteristics make helium very hard to contain. If a system has a leak, helium will escape. Helium gas is therefore used to test high vacuum systems, fuel systems and other containments for leaks.