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.
The term hydride is used in a generic sense to indicate compounds of the type M x H y and not necessarily to indicate that any compounds listed behave chemically as hydrides. In compounds of helium (where known), the most common oxidation numbers of helium are: 0.he term hydride is used in a generic sense to indicate compounds of the type M x H y and not necessarily to indicate that any compounds listed behave chemically as hydrides. In compounds of helium (where known), the most common oxidation numbers of helium are: 0.