It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which lanthanum is the first and the prototype. Like atomic hydrogen, the assemblage can exist in a number of energy levels. At the temperature in the gas discharge tube, more atoms are in the n = 3 than the n ≥ 4 levels. Gold is thought to have been produced in supernova nucleosynthesis, from the collision of neutron stars. Antimony is a lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite. Melting Point: -259.14 °C (14.009985 K, -434.45203 °F) Boiling Point: -252.87 °C (20.280005 K, -423.166 °F) Number of Protons/Electrons: 1. Atomic orbitals can be the hydrogen-like "orbitals" which are exact solutions to the Schrödinger equation for a hydrogen-like "atom" (i.e., an atom with one electron). It readily forms hard, stable carbides in alloys, and for this reason most of world production of the element (about 80%) is used in steel alloys, including high-strength alloys and superalloys. Curium is a hard, dense, silvery metal with a relatively high melting point and boiling point for an actinide. Lanthanum is a chemical element with atomic number 57 which means there are 57 protons and 57 electrons in the atomic structure. What is Radius and Density of Atomic Nucleus - Definition, What is Uranium in the Environment - Definition, What is Quark in the Standard Model - Definition, What is Electron in the Standard Model - Definition. The chemical symbol for Holmium is Ho. In nuclear industry, especially natural and artificial samarium 149 has an important impact on the operation of a nuclear reactor. Rhodium is a chemical element with atomic number 45 which means there are 45 protons and 45 electrons in the atomic structure. Calcium is an alkaline earth metal, it is a reactive pale yellow metal that forms a dark oxide-nitride layer when exposed to air. ERNEST. Scandium is a silvery-white metallic d-block element, it has historically been sometimes classified as a rare-earth element, together with yttrium and the lanthanides. However, this assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. It is an intensive property, which is mathematically defined as mass divided by volume: In words, the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance. The number of atoms or molecules (n) in a mass (m) of a pure material having atomic or molecular weight (M) is easily computed from the following equation using Avogadro's number (NA = 6.022×10 23 atoms or molecules per gram-mole): M mN n A (1) In some situations, the atomic number density (N), which is the concentration of atoms or molecules per The Van der Waals radius, rw, of an atom is the radius of an imaginary hard sphere representing the distance of closest approach for another atom. Carbon is one of the few elements known since antiquity. All of the alkali metals have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge – a cation, which combines with anions to form salts. 17. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. Hafnium is a chemical element with atomic number 72 which means there are 72 protons and 72 electrons in the atomic structure. The chemical symbol for Actinium is Ac. Discoverer: McMillan, Edwin M. and Abelson, Philip H. Discoverer: Glenn T. Seaborg, Joseph W. Kennedy, Edward M. McMillan, Arthur C. Wohl, Discoverer: Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso, Discoverer: Glenn T. Seaborg, Ralph A. James, Albert Ghiorso, Discoverer: Stanley G. Thompson, Glenn T. Seaborg, Kenneth Street, Jr., Albert Ghiorso, Discoverer: Stanley G. Thompson, Glenn T. Seaborg, Bernard G. Harvey, Gregory R. Choppin, Albert Ghiorso, Discoverer: Albert Ghiorso, Glenn T. Seaborg, Torbørn Sikkeland, John R. Walton, Discoverer: Albert Ghiorso, Torbjørn Sikkeland, Almon E. Larsh, Robert M. Latimer, Copyright 2021 Periodic Table | All Rights Reserved |. The chemical symbol for Rhodium is Rh. The chemical symbol for Zinc is Zn. It is believed to be the first atom produced in our Universe after the Big Bang, and all other elements were further produced from hydrogen as a result of nuclear fusion. The chemical symbol for Niobium is Nb. The chemical symbol for Sodium is Na. Aluminium is a silvery-white, soft, nonmagnetic, ductile metal in the boron group. The chemical symbol for Yttrium is Y. Yttrium is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a “rare-earth element”. Barium is the fifth element in group 2 and is a soft, silvery alkaline earth metal. The chemical symbol for Radon is Rn. It is believed to be the first atom produced in our Universe after the Big Bang, and all other elements were further produced from hydrogen as a result of nuclear fusion. But its density pales by comparison to the densities of exotic astronomical objects such as white dwarf stars and neutron stars. Hydrogen is a chemical element having the atomic number 1 and is given in the symbol H. An atom of hydrogen is composed of one proton and no neutrons in the nucleus; it has one electron in its 1s orbital. The chemical symbol for Californium is Cf. Zirconium is a lustrous, grey-white, strong transition metal that resembles hafnium and, to a lesser extent, titanium. The chemical symbol for Tellurium is Te. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide. Although neodymium is classed as a rare earth, it is a fairly common element. A freshly exposed surface of pure copper has a reddish-orange color. Europium is a moderately hard, silvery metal which readily oxidizes in air and water. Since the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance, it is obvious, the density of a substance strongly depends on its atomic mass and also on the atomic number density (N; atoms/cm3). Lanthanoids comprise the 15 metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium. See more. Iodine is the least abundant of the stable halogens, being the sixty-first most abundant element. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity, behind only oxygen and fluorine. The atomic radius of a chemical element is a measure of the distance out to which the electron cloud extends from the nucleus. Erbium is a silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. The chemical symbol for Tantalum is Ta. Samarium is a chemical element with atomic number 62 which means there are 62 protons and 62 electrons in the atomic structure. Francium is an alkali metal, that has one valence electron. Helium is a chemical element with atomic number 2 which means there are 2 protons and 2 electrons in the atomic structure. Palladium is a chemical element with atomic number 46 which means there are 46 protons and 46 electrons in the atomic structure. The chemical symbol for Uranium is U. These elements, along with the chemically similar elements scandium and yttrium, are often collectively known as the rare earth elements. Tungsten is an intrinsically brittle and hard material, making it difficult to work. The chemical symbol for Neodymium is Nd. Two types of molecular hydrogen (ortho and para) are known. The chemical symbol for Platinum is Pt. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine. Titanium is a chemical element with atomic number 22 which means there are 22 protons and 22 electrons in the atomic structure. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.. These condensers use tubes that are usually made of stainless steel, copper alloys, or titanium depending on several selection criteria (such as thermal conductivity or corrosion resistance). The chemical symbol for Iodine is I. Iodine is the heaviest of the stable halogens, it exists as a lustrous, purple-black metallic solid at standard conditions that sublimes readily to form a violet gas. Cerium is the second element in the lanthanide series. Berkelium is a member of the actinide and transuranium element series. The chemical symbol for Astatine is At. Discoverer: Corson, Dale R. and Mackenzie, K. R. The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium. Graphic courtesy of ChemicalElements.com Neon is a chemical element with atomic number 10 which means there are 10 protons and 10 electrons in the atomic structure. The chemical symbol for Krypton is Kr. Iridium is a very hard, brittle, silvery-white transition metal of the platinum group, iridium is generally credited with being the second densest element (after osmium). All isotopes of radium are highly radioactive, with the most stable isotope being radium-226. Caesium is a soft, silvery-gold alkali metal with a melting point of 28.5 °C, which makes it one of only five elemental metals that are liquid at or near room temperature. Vanadium is a chemical element with atomic number 23 which means there are 23 protons and 23 electrons in the atomic structure. The chemical symbol for Palladium is Pd. Neodymium is a chemical element with atomic number 60 which means there are 60 protons and 60 electrons in the atomic structure. It has an estimated density of 40.7 x 103 kg/m3. Lead is a chemical element with atomic number 82 which means there are 82 protons and 82 electrons in the atomic structure. Fermium is a member of the actinide series. Basic Information. The chemical symbol for Technetium is Tc. The chemical symbol for Gold is Au. The chemical symbol for Fermium is Fm. Furthermore, all isotopes of an element typically have the same number of protons and different number of neutrons. The atomic radii decrease across the periodic table because as the atomic number increases, the number of protons increases across the period, but the extra electrons are only added to the same quantum shell. Tellurium is a brittle, mildly toxic, rare, silver-white metalloid. The chemical symbol for Polonium is Po. Oxygen is a colourless, odourless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air. Because a sample of hydrogen contains a large number of atoms, the intensity of the various lines in a line spectrum depends on the number of atoms in each excited state. Unstable subatomic particle. The chemical symbol for Hydrogen is H. With a standard atomic weight of circa 1.008, hydrogen is the lightest element on the periodic table. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs. The chemical symbol for Mercury is Hg. The electron configuration of hydrogen is given … Curium is a chemical element with atomic number 96 which means there are 96 protons and 96 electrons in the atomic structure. Antimony is a chemical element with atomic number 51 which means there are 51 protons and 51 electrons in the atomic structure. Mercury is a chemical element with atomic number 80 which means there are 80 protons and 80 electrons in the atomic structure. Manganese is a metal with important industrial metal alloy uses, particularly in stainless steels. Cadmium is a chemical element with atomic number 48 which means there are 48 protons and 48 electrons in the atomic structure. Osmium is the densest naturally occurring element, with a density of 22.59 g/cm3. The chemical symbol for Xenon is Xe. State of Hydrogen is Gas at standard temperature and pressure E. Discoverer: De Marignac, Charles Galissard, Discoverer: De Marignac, Jean Charles Galissard, Discoverer: Göhring, Otto and Fajans, Kasimir. Gadolinium is a chemical element with atomic number 64 which means there are 64 protons and 64 electrons in the atomic structure. Uranium is a chemical element with atomic number 92 which means there are 92 protons and 92 electrons in the atomic structure. It rarely occurs in its elemental state or as pure ore compounds in the Earth’s crust. Atomic number of hydrogen crossword clue. It is a synthetic element (first synthesised at Hasse in Germany) and radioactive. It is also sometimes considered the first element of the 6th-period transition metals and is traditionally counted among the rare earth elements. Thulium is the thirteenth and third-last element in the lanthanide series. This equilibrium also known as “samarium 149 reservoir”, since all of this promethium must undergo a decay to samarium. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Californium is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium). The chemical symbol for Argon is Ar. The chemical properties of this silvery gray, crystalline transition metal are intermediate between rhenium and manganese. As a result, the electron cloud contracts and the atomic radius decreases. A major development was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Tellurium is far more common in the universe as a whole than on Earth. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Discoverer: Marinsky, Jacob A. and Coryell, Charles D. and Glendenin, Lawerence. Element Hydrogen (H), Group 1, Atomic Number 1, s-block, Mass 1.008. Atomic number of hydrogen. Hydrogen definition, a colorless, odorless, flammable gas that combines chemically with oxygen to form water: the lightest of the known elements. Samarium is a typical member of the lanthanide series, it is a moderately hard silvery metal that readily oxidizes in air. Argon is a chemical element with atomic number 18 which means there are 18 protons and 18 electrons in the atomic structure. The Standard English unit is pounds mass per cubic foot (lbm/ft3). Cerium is a chemical element with atomic number 58 which means there are 58 protons and 58 electrons in the atomic structure. With a standard atomic weight of circa 1.008, hydrogen is the lightest element on the periodic table. Astatine is the rarest naturally occurring element on the Earth’s crust. Calcium is a chemical element with atomic number 20 which means there are 20 protons and 20 electrons in the atomic structure. Lanthanum is a soft, ductile, silvery-white metal that tarnishes rapidly when exposed to air and is soft enough to be cut with a knife. Hydrogen is the most abundant element in the universe. Radon is a chemical element with atomic number 86 which means there are 86 protons and 86 electrons in the atomic structure. The chemical symbol for Hafnium is Hf. Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name, kohl. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. Thorium metal is silvery and tarnishes black when exposed to air, forming the dioxide. Einsteinium is a chemical element with atomic number 99 which means there are 99 protons and 99 electrons in the atomic structure. Entire website is based on our own personal perspectives, and do not represent the views of any company of nuclear industry. The element number or atomic number is the number of protons present in the atom. Phosphorus is a chemical element with atomic number 15 which means there are 15 protons and 15 electrons in the atomic structure. Hafnium’s large neutron capture cross-section makes it a good material for neutron absorption in control rods in nuclear power plants, but at the same time requires that it be removed from the neutron-transparent corrosion-resistant zirconium alloys used in nuclear reactors. Indeed, atomic hydrogen is the most crucial component in the gas-phase mixture, which drives the whole chemical process and performs a number of important functions [33], such as: • Atomic H can etch sp 2 carbon many times faster than sp 3 carbon; • It consists of two protons and two electrons held together by electrostatic forces. Although classified as a rare earth element, samarium is the 40th most abundant element in the Earth’s crust and is more common than such metals as tin. Typical densities of various substances are at atmospheric pressure. The chemical symbol for Helium is He. Lead is soft and malleable, and has a relatively low melting point. Its atomic number is 1, and hydrogen has one electron and one proton. Consequently, the smallest atom is helium with a radius of 32 pm, while one of the largest is caesium at 225 pm. Neptunium is the first transuranic element. Sodium is an alkali metal, being in group 1 of the periodic table, because it has a single electron in its outer shell that it readily donates, creating a positively charged atom—the Na+ cation. Astatine is a chemical element with atomic number 85 which means there are 85 protons and 85 electrons in the atomic structure. Platinum is one of the least reactive metals. Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, including rapid oxidation in air. The chemical symbol for Iridium is Ir. Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. Therefore, there are various non-equivalent definitions of atomic radius. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. There are over 100 different borate minerals, but the most common are: borax, kernite, ulexite etc. Discoverer: Scientists at Dubna, Russia (1964)/Albert Ghiorso et. It is even less abundant than the so-called rare earths. The chemical symbol for Promethium is Pm. Osmium is a hard, brittle, bluish-white transition metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Nickel is a chemical element with atomic number 28 which means there are 28 protons and 28 electrons in the atomic structure. Thorium is a chemical element with atomic number 90 which means there are 90 protons and 90 electrons in the atomic structure. It occurs on Earth as the decay product of various heavier elements. The name of the gas is formed from two Greek words, meaning water and forming, so this is the element which creates water. Its abundance in rocky planets like Earth is due to its abundant production by fusion in high-mass stars. It must be noted, atoms lack a well-defined outer boundary. We most recently saw this clue in 'The New York Times Mini' on Thursday, 15 October 2020 with the answer being ONE, we also found ONE to be the most popular answer for this clue. The chemical symbol for Protactinium is Pa. Protactinium is a dense, silvery-gray metal which readily reacts with oxygen, water vapor and inorganic acids. Tungsten is a chemical element with atomic number 74 which means there are 74 protons and 74 electrons in the atomic structure. Lawrencium is a chemical element with atomic number 103 which means there are 103 protons and 103 electrons in the atomic structure. Under standard conditions, it is the lightest metal and the lightest solid element. The chemical symbol for Calcium is Ca. The chemical symbol for Ytterbium is Yb. It explains how we use cookies (and other locally stored data technologies), how third-party cookies are used on our Website, and how you can manage your cookie options. The chemical symbol for Americium is Am. Sodium is a soft, silvery-white, highly reactive metal. Silicon is a hard and brittle crystalline solid with a blue-grey metallic lustre, it is a tetravalent metalloid and semiconductor. Chromium is a chemical element with atomic number 24 which means there are 24 protons and 24 electrons in the atomic structure. www.nuclear-power.net. Chlorine is a chemical element with atomic number 17 which means there are 17 protons and 17 electrons in the atomic structure. The chemical symbol for Neon is Ne. Bismuth is a chemical element with atomic number 83 which means there are 83 protons and 83 electrons in the atomic structure. (1969), Discoverer: Scientists at Dubna, Russia (1967)/Lawrence Berkeley Laboratory (1970), Discoverer: Armbruster, Paula and Muenzenberg, Dr. Gottfried, Element Category: unknown, probably a transition metal, Discoverer: David Anderson, Ruhani Rabin, Team Updraft, Element Category: unknown, probably a post-transition metal, Discoverer: Hisinger, Wilhelm and Berzelius, Jöns Jacob/Klaproth, Martin Heinrich. The New York Times Mini Crossword is a mini version for the NYT Crossword and contains fewer clues then the main crossword. Natural boron consists primarily of two stable isotopes, 11B (80.1%) and 10B (19.9%). Radon is a radioactive, colorless, odorless, tasteless noble gas. Tin is a chemical element with atomic number 50 which means there are 50 protons and 50 electrons in the atomic structure. The chemical symbol for Erbium is Er. The mention of names of specific companies or products does not imply any intention to infringe their proprietary rights. The chemical symbol for Radium is Ra. In the periodic table, potassium is one of the alkali metals. Francium is a highly radioactive metal that decays into astatine, radium, and radon. The chemical symbol for Plutonium is Pu. Terbium is a chemical element with atomic number 65 which means there are 65 protons and 65 electrons in the atomic structure. It is a soft, silvery-white alkali metal. Hydrogen: Symbol: H: Atomic Number: 1: Atomic Mass: 1.00794 atomic mass units: Number of Protons: 1: Number of Neutrons: 0: Number of Electrons: 1: Melting Point-259.14° C: Boiling Point-252.87° C: Density.08988 grams per cubic centimeter: Normal Phase: Gas: Family: Nonmetal: Period: 1: … Lead is widely used as a gamma shield. Very soft and malleable, indium has a melting point higher than sodium and gallium, but lower than lithium and tin. Tin is a post-transition metal in group 14 of the periodic table. Krypton is a member of group 18 (noble gases) elements. Posted by krist on 15 October 2020, 3:25 am. Fermium is a chemical element with atomic number 100 which means there are 100 protons and 100 electrons in the atomic structure. The chemical symbol for Arsenic is As. Lawrencium is the final member of the actinide series. Atomic number of hydrogen is a 4 word phrase featuring 25 letters. We can count these states for each value of the principal quantum number, n = 1, 2, 3. The chemical symbol for Bismuth is Bi. Gold is a chemical element with atomic number 79 which means there are 79 protons and 79 electrons in the atomic structure. Ruthenium is a rare transition metal belonging to the platinum group of the periodic table. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. In nuclear industry cadmium is commonly used as a thermal neutron absorber due to very high neutron absorption cross-section of 113Cd. The chemical symbol for Titanium is Ti. Because of its high chemical reactivity, barium is never found in nature as a free element. Dysprosium is a chemical element with atomic number 66 which means there are 66 protons and 66 electrons in the atomic structure. On the atomic scale, physicists have found that quantum mechanics describes things very well on that scale. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. The chemical symbol for Caesium is Cs. Hassium is a chemical element with symbol Hs and atomic number 108. Non-remnant stars are mainly composed of hydrogen in the plasma state. It is occasionally found in native form as elemental crystals. The chemical symbol for Dysprosium is Dy. Thallium is a chemical element with atomic number 81 which means there are 81 protons and 81 electrons in the atomic structure. Hafnium is a lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. However, the total energy depends on the principal quantum number only, which means that we can use Equation 8.2.5 and the number of states counted. Cerium is also traditionally considered one of the rare-earth elements. Francium is the second-least electronegative element, behind only caesium, and is the second rarest naturally occurring element (after astatine). In fact their absorption cross-sections are the highest among all stable isotopes. Technetium is the lightest element whose isotopes are all radioactive; none are stable. Lutetium is a silvery white metal, which resists corrosion in dry air, but not in moist air. The chemical symbol for Lithium is Li. The chemical symbol for Neptunium is Np. Therefore, the effective nuclear charge towards the outermost electrons increases, drawing the outermost electrons closer. Cadmium is a soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Name: Hydrogen. The name xenon for this gas comes from the Greek word ξένον [xenon], neuter singular form of ξένος [xenos], meaning ‘foreign(er)’, ‘strange(r)’, or ‘guest’. Lutetium is a chemical element with atomic number 71 which means there are 71 protons and 71 electrons in the atomic structure. Melting point of Hydrogen is -259,1 °C and its the boiling point is -252,9 °C. The chemical symbol for Fluorine is F. Fluorine is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. Ytterbium is a chemical element with atomic number 70 which means there are 70 protons and 70 electrons in the atomic structure. and Gay-Lussac, L.-J. Protium (hydrogen-1) has an atomic mass of 1.00782504, and is a stable isotope. Aluminum is a chemical element with atomic number 13 which means there are 13 protons and 13 electrons in the atomic structure. At 0.099%, phosphorus is the most abundant pnictogen in the Earth’s crust. The chemical symbol for Scandium is Sc. MUON. Titanium is a lustrous transition metal with a silver color, low density, and high strength. Manganese is a chemical element with atomic number 25 which means there are 25 protons and 25 electrons in the atomic structure. Rhodium is a rare, silvery-white, hard, corrosion resistant and chemically inert transition metal. This element is a gas at room temperature. Tellurium is chemically related to selenium and sulfur. Uranium has the highest atomic weight of the primordially occurring elements. The chemical symbol for Iron is Fe. Iron is a metal in the first transition series. The chemical symbol for Germanium is Ge. Due to the quantum nature of electrons, the electrons are not point particles, they are smeared out over the whole atom. Our Website follows all legal requirements to protect your privacy. Atomic Mass: 1.00794 amu. Polonium is a rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. In nuclear industry gadolinium is commonly used as a neutron absorber due to very high neutron absorbtion cross-section of two isotopes 155Gd and 157Gd. The commercial use of beryllium requires the use of appropriate dust control equipment and industrial controls at all times because of the toxicity of inhaled beryllium-containing dusts that can cause a chronic life-threatening allergic disease in some people called berylliosis. Known as the most abundant and the lightest chemical element in our Universe, hydrogen is a type of gas without color and smell, which also has the lowest density of all gases. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. The Cookies Statement is part of our Privacy Policy. The chemical symbol for Curium is Cm. Because of its closed-shell electron configuration, its density and melting and boiling points differ significantly from those of most other lanthanides. Particle locations in quantum mechanics are not at an exact position, they are described by a probability density function. Boiling point of Hydrogen in Kelvin is 20.28 K. Hydrogen melting point is -259,1 °C. In nuclear industry boron is commonly used as a neutron absorber due to the high neutron cross-section of isotope 10B. Silicon is a chemical element with atomic number 14 which means there are 14 protons and 14 electrons in the atomic structure.