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 2 protons and 2 neutrons. A particle number of 2 is especially stable in a nucleus. This is because of the shell structure, and it's analogous to the stability of the noble gases in atomic physics. Helium has 2 protons and 2 neutrons. A particle number of 2 is especially stable in a nucleus. This is because of the shell structure, and it's analogous to the stability of the noble gases in atomic physics. For more on this, google magic number.. And merely saying helium is grossly misleading. Alpha particle is specifically helium 4. Helium 4, like helium atom, has extreme stability because of closed shells. 2 electrons of opposite spins both in their lowest state, 2 protons of opposite spin ditto, 2 neutrons of opposite spin ditto. Nothing else matches that stability.