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The term comes from an obsolete Middle English philosophical word that Alpher said he found in Webster's dictionary. [5] The word means something along the lines of "primordial substance from which all matter is formed" (that in ancient mythology of many different cultures was called the cosmic egg [6]) and ultimately derives from the hūlē (Ancient Greek: ὕλη, romanized: matter ...
Helium has a negative Joule–Thomson coefficient at normal ambient temperatures, meaning it heats up when allowed to freely expand. Only below its Joule–Thomson inversion temperature (of about 32 to 50 K at 1 atmosphere) does it cool upon free expansion. [ 30 ]
Jellium, also known as the uniform electron gas (UEG) or homogeneous electron gas (HEG), is a quantum mechanical model of interacting electrons in a solid where the positive charges (i.e. atomic nuclei) are assumed to be uniformly distributed in space; the electron density is a uniform quantity as well in space.
A helium atom is an atom of the chemical element helium.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.
41 of the 118 known elements have names associated with, or specifically named for, places around the world or among astronomical objects. 32 of these have names tied to the places on Earth, and the other nine are named after to Solar System objects: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium after their respective ...
Atomicity is the total number of atoms present in a molecule of an element. For example, each molecule of oxygen (O 2) is composed of two oxygen atoms.Therefore, the atomicity of oxygen is 2.
Earlier symbols for chemical elements stem from classical Latin and Greek vocabulary. For some elements, this is because the material was known in ancient times, while for others, the name is a more recent invention.
The Meaning of It All: Thoughts of a Citizen Scientist is a non-fiction book by the Nobel Prize-winning physicist Richard Feynman. It is a collection of three previously unpublished public lectures given by Feynman in 1963. [1] The book was first published in hardcover in 1998, ten years after Feynman's death, by Addison–Wesley.