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Helium is found in large amounts in minerals of uranium and thorium, including uraninite and its varieties cleveite and pitchblende, [20] [137] carnotite and monazite (a group name; "monazite" usually refers to monazite-(Ce)), [138] [139] because they emit alpha particles (helium nuclei, He 2+) to which electrons immediately combine as soon as ...
Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with two neutrons, depending on the isotope, held together by the strong force. Unlike for hydrogen , a closed-form solution to the Schrödinger equation for the helium atom has not been found.
A helion (symbol h) is the nucleus of a helium atom, a doubly positively charged cation.The term helion is a portmanteau of helium and ion, and in practice refers specifically to the nucleus of the helium-3 isotope, consisting of two protons and one neutron.
Helium is the smallest and the lightest noble gas and one of the most unreactive elements, so it was commonly considered that helium compounds cannot exist at all, or at least under normal conditions. [1] Helium's first ionization energy of 24.57 eV is the highest of any element. [2]
Pure helium-3 gas boils at 3.19 K compared with helium-4 at 4.23 K, and its critical point is also lower at 3.35 K, compared with helium-4 at 5.2 K. Helium-3 has less than half the density of helium-4 when it is at its boiling point: 59 g/L compared to 125 g/L of helium-4 at a pressure of one atmosphere.
Secondly, he found the charge-to-mass ratio of alpha particles to be half that of the hydrogen ion. Rutherford proposed three explanations: 1) an alpha particle is a hydrogen molecule (H 2) with a charge of 1 e; 2) an alpha particle is an atom of helium with a charge of 2 e; 3) an alpha particle is half a helium atom with a charge of 1 e.
A FBI document obtained by Wikileaks details the symbols and logos used by pedophiles to identify sexual preferences. According to the document members of pedophilic organizations use of ...
Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols, normally consist of one or two letters from the Latin alphabet and are written with the first letter capitalised.