Helium Explorer is an open source block explorer providing detailed blockchain data from the Helium network. Helium is a 2014 Danish short drama film directed by Anders Walter. Alfred is a young boy staying in a hospital who suffers from an undisclosed terminal illness. Enzo, a janitor at the hospital, meets Alfred while working and the two develop a friendship. Enzo tells Alfred of Helium, an attractive alternative to Heaven, because Alfred. Helium is found everywhere in the Universe and is the second most common element, just behind hydrogen. As far as we're concerned, helium is a 'happy' element. It is inert, because its outermost electron orbital is full with two electrons. You can also find helium in compressed air tanks, lasers, and as coolants in nuclear reactors. Helium is a member of the noble gas family. The noble gases are the elements in Group 18 (VIIIA) of the periodic table. The periodic table is a chart that shows how the elements are related to one another. The noble gases are also called the inert gases.
The helium ground state consists of two identical 1s electrons. The energy required to remove one of them is the highest ionization energy of any atom in the periodic table: 24.6 electron volts. The energy required to remove the second electron is 54.4 eV, as would be expected by modeling it after the hydrogen energy levels. The He+ ion is just like a hydrogen atom with two units of charge in the nucleus. Since the hydrogenic energy levels depend upon the square of the nuclear charge, the energy of the remaining helium electron should be just 4x(-13.6 eV) = -54.4 eV as observed.
How Rare Is Helium
The fact that the second electron is less tightly bound can be interpreted as a shielding effect; the other electron partly shields the second electron from the full charge of the nucleus. Its energy can be used to model the effective shielding as follows.
Another way to view the energy is to say that the repulsion of the electrons contributes a positive potential energy which partially offsets the negative potential energy contributed by the attractive electric force of the nuclear charge. The description of any electron in a multi-electron atom must find a way to characterize the effect of the other electrons on the energy.
| Helium spectrum | Why do levels vary with orbital quantum number? |
Is Helium Flammable
| Energy levels of multi-electron atoms |