It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities. 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. Number of protons = 11. Barium is the fifth element in group 2 and is a soft, silvery alkaline earth metal. The chemical symbol for Lead is Pb. The chemical symbol for Actinium is Ac. Atomic Number of Hydrogen. The chemical symbol for Gallium is Ga. Gallium has similarities to the other metals of the group, aluminium, indium, and thallium. In nuclear industry, especially artificial xenon 135 has a tremendous impact on the operation of a nuclear reactor. It is the electrons that are responsible for the chemical bavavior of atoms, and which identify the various chemical elements. The chemical symbol for Lutetium is Lu. Hydrogen. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons in its nucleus. Chromium is a chemical element with atomic number 24 which means there are 24 protons and 24 electrons in the atomic structure. The chemical symbol for Lawrencium is Lr. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use. It has the lowest density (0.0899*10-3 g.cm-3 at 20 °C) as compared to all other gases. Classified as a nonmetal, Hydrogen is a gas at room temperature. Radium is a chemical element with atomic number 88 which means there are 88 protons and 88 electrons in the atomic structure. Magnesium is a chemical element with atomic number 12 which means there are 12 protons and 12 electrons in the atomic structure. The chemical symbol for Manganese is Mn. 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. Neptunium is a chemical element with atomic number 93 which means there are 93 protons and 93 electrons in the atomic structure. Cerium is a soft, ductile and silvery-white metal that tarnishes when exposed to air, and it is soft enough to be cut with a knife. If necessary, click on Reset Nucleus to see the simulation again. Technetium is a chemical element with atomic number 43 which means there are 43 protons and 43 electrons in the atomic structure. The most important use of hydrogen in the world is in ammonia manufacture for the fertilizer market. 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. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non- Englisch-Deutsch-Übersetzungen für Hydrogen im Online-Wörterbuch dict.cc (Deutschwörterbuch). Rubidium is a soft, silvery-white metallic element of the alkali metal group, with an atomic mass of 85.4678. Its boiling point is the lowest among all the elements. Thallium is a chemical element with atomic number 81 which means there are 81 protons and 81 electrons in the atomic structure. It is a noble gas, non-metal and is the most abundant element in the universe. The New York Times Mini Crossword is a mini version for the NYT Crossword and contains fewer clues then the main crossword. The variables give the position of the electron relative to the proton in spherical coordinates. It is useful to know that the value of \(hcR = 13.6 eV\). It is the fifth most abundant element in Earth’s crust and the third most abundant metal, after iron and aluminium. These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, and the noble gases. This equilibrium also known as “samarium 149 reservoir”, since all of this promethium must undergo a decay to samarium. Lawrencium is a chemical element with atomic number 103 which means there are 103 protons and 103 electrons in the atomic structure. The chemical symbol for Iron is Fe. The chemical symbol for Samarium is Sm. It is non-toxic and nonmetallic at standard conditions (standard temperature and pressure). Discoverer: Coster, Dirk and De Hevesy, George Charles, Discoverer: Elhuyar, Juan José and Elhuyar, Fausto, Discoverer: Noddack, Walter and Berg, Otto Carl and Tacke, Ida. We use cookies to ensure that we give you the best experience on our website. Carbon is one of the few elements known since antiquity. Chemical symbol for Hydrogen is H. Number of protons in Hydrogen is 1. Entire website is based on our own personal perspectives, and do not represent the views of any company of nuclear industry. Hydrogen is mostly used in the petroleum and chemical industries. 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. The chemical symbol for Rubidium is Rb. All of its isotopes are radioactive. Radon is a radioactive, colorless, odorless, tasteless noble gas. 113Cd has specific absorption cross-section. Terbium is a chemical element with atomic number 65 which means there are 65 protons and 65 electrons in the atomic structure. 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. It is a noble gas, non-metal and is the most abundant element in the universe. One more very important point is: hydrogen is now seen as a source of clean eco-friendly fuel of the future, which will help the humanity to solve the problem of pollution and being gas/oil dependent. Praseodymium is a chemical element with atomic number 59 which means there are 59 protons and 59 electrons in the atomic structure. Chlorine is a chemical element with atomic number 17 which means there are 17 protons and 17 electrons in the atomic structure. Hydrogen's atomic number is 1 because all hydrogen atoms contain exactly one proton. Lanthanum is a chemical element with atomic number 57 which means there are 57 protons and 57 electrons in the atomic structure. The chemical symbol for Hydrogen is H. The atom consist of a small but massive nucleus surrounded by a cloud of rapidly moving electrons. Mercury is commonly known as quicksilver and was formerly named hydrargyrum. Ruthenium is a rare transition metal belonging to the platinum group of the periodic table. Thorium is a naturally-occurring element and it is estimated to be about three times more abundant than uranium. Only about 5×10−8% of all matter in the universe is europium. Element Hydrogen (H), Group 1, Atomic Number 1, s-block, Mass 1.008. Yttrium is a chemical element with atomic number 39 which means there are 39 protons and 39 electrons in the atomic structure. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. The most pr… There are over 100 different borate minerals, but the most common are: borax, kernite, ulexite etc. It’s one of the main compounds of water and of all organic matter, and it’s widely spread not only in The Earth but also in the entire Universe. Gold is a transition metal and a group 11 element. Hydrogen= 1; Helium=2; Lithium=3; Beryllium=4; Boron=5; Carbon=6; Nitogen=7; Oxygen=8; Finding the Atomic Number. Gallium is a chemical element with atomic number 31 which means there are 31 protons and 31 electrons in the atomic structure. First element in the periodic table. The chemical symbol for Thallium is Tl. The chemical symbol for Gadolinium is Gd. al. Hydrogen is the element that is atomic number 1 on the periodic table. Nearly all technetium is produced synthetically, and only minute amounts are found in the Earth’s crust. Tungsten is an intrinsically brittle and hard material, making it difficult to work. Pure germanium is a semiconductor with an appearance similar to elemental silicon. Americium is a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was named after the Americas. 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 Nitrogen is N. Nitrogen is a colourless, odourless unreactive gas that forms about 78% of the earth’s atmosphere. Osmium is the densest naturally occurring element, with a density of 22.59 g/cm3. We can see here that the atomic numbers (or number … The chemical symbol for Ruthenium is Ru. The chemical symbol for Chlorine is Cl. It is the lightest element that can be found on earth. Atomic number of few elements. Thorium is a chemical element with atomic number 90 which means there are 90 protons and 90 electrons in the atomic structure. Since atoms are neutral, the number of electrons in an atom is equal to the number of protons. Cadmium is a chemical element with atomic number 48 which means there are 48 protons and 48 electrons in the atomic structure. 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. Thus the atomic number of Na atom = number of electrons = number of protons = 11. Nobelium is the tenth transuranic element and is the penultimate member of the actinide series. Like all elements with atomic number over 100, lawrencium can only be produced in particle accelerators by bombarding lighter elements with charged particles. Neptunium is the first transuranic element. The orientation of an orbital in space. Pause the simulation immediately after the decay occurs. Its density is about 70% higher than that of lead, and slightly lower than that of gold or tungsten. Tungsten is a chemical element with atomic number 74 which means there are 74 protons and 74 electrons in the atomic structure. Ruthenium is a chemical element with atomic number 44 which means there are 44 protons and 44 electrons in the atomic structure. Platinum is one of the least reactive metals. Naturally occurring potassium is composed of three isotopes, of which 40K is radioactive. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. Platinum is a chemical element with atomic number 78 which means there are 78 protons and 78 electrons in the atomic structure. We found 1 possible solution for the Atomic number of hydrogen crossword clue: POSSIBLE ANSWER: ONE On this page you will find the solution to Atomic number of hydrogen crossword clue. Hydrogen (H) is a tasteless, colorless, odorless gas and has the atomic number 1. The chemical symbol for Aluminum is Al. The chemical symbol for Selenium is Se. Its one of the main compounds of water and of all organic matter, and its widely spread not only in The Earth but also in the entire Universe. This clue was last seen on New York Times Mini Crossword October 15 2020 Answers In case the clue doesn’t fit or there’s something […] Bismuth is a chemical element with atomic number 83 which means there are 83 protons and 83 electrons in the atomic structure. Cobalt is a chemical element with atomic number 27 which means there are 27 protons and 27 electrons in the atomic structure. It is occasionally found in native form as elemental crystals. It is extensively used in a large variety of industrial branches, from chemical industry (producing fertilizers, etc) to electronic (substance producing) and food industry, etc. Significant concentrations of boron occur on the Earth in compounds known as the borate minerals. Total number of protons in the nucleus is called the … Holmium is a relatively soft and malleable silvery-white metal. 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 atomic number of hydrogen is 1. There are three isotopes of hydrogen namely, protium 1H1, deuterium 1H2 or D and lastly tritium 1H3 or T. at 0℃ and one atmosphere pressure. It is the Pauli exclusion principle that requires the electrons in an atom to occupy different energy levels instead of them all condensing in the ground state. There are three isotopes of hydrogen namely, protium 1H1, deuterium 1H2 or D and lastly tritium 1H3 or T. The isotopes are different because of the different number of neutrons present in them. Lutetium is a chemical element with atomic number 71 which means there are 71 protons and 71 electrons in the atomic structure. What are the particles that are emitted from the nucleus? Hydrogen is a chemical element with symbol H and atomic number 1. Hydrogen (H), for example , consist of one electron and one proton. Hence the atomic number of hydrogen is 1. and Gay-Lussac, L.-J. It is fairly soft and slowly tarnishes in air. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. The chemical symbol for Polonium is Po. 15. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. Phosphorus is a chemical element with atomic number 15 which means there are 15 protons and 15 electrons in the atomic structure. In nuclear industry, especially natural and artificial samarium 149 has an important impact on the operation of a nuclear reactor. “Atomic number of hydrogen” We are sharing answer for NYT Mini Crossword of October 15 2020 for clue that we published below. Atomic hydrogen is used for in-situ cleaning of Si substrates, leading to significant reductions in surface contamination. Uranium has the highest atomic weight of the primordially occurring elements. Atomic hydrogen irradiation has also been used during growth of GaAs on Si substrates to achieve lower defect densities. Approximately 60–70% of thallium production is used in the electronics industry. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. Loosely speaking, the existence or construction of a periodic table of elements creates an ordering of the elements, and so they can be numbered in order. 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 |. From the given information, we can find out the atomic number of an element in the following ways. Neptunium metal is silvery and tarnishes when exposed to air. The chemical symbol for Cadmium is Cd. Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. Zirconium is mainly used as a refractory and opacifier, although small amounts are used as an alloying agent for its strong resistance to corrosion. Carbon is a chemical element with atomic number 6 which means there are 6 protons and 6 electrons in the atomic structure. It rarely occurs in its elemental state or as pure ore compounds in the Earth’s crust. Hydrogen is a chemical element. Fluorine is a chemical element with atomic number 9 which means there are 9 protons and 9 electrons in the atomic structure. 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. The chemical symbol for Berkelium is Bk. Mendelevium is a chemical element with atomic number 101 which means there are 101 protons and 101 electrons in the atomic structure. 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: Cost: $1.00 per gram . Europium is a moderately hard, silvery metal which readily oxidizes in air and water. 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’. Atomic Number – Does it conserve in a nuclear reaction? In protium, there is no presence of neutrons, whereas in deuterium we have one neutron and in tritium, we have two neutrons. The chemical symbol for Lanthanum is La. Under standard conditions, it is the lightest metal and the lightest solid element. Titanium can be used in surface condensers. Gallium does not occur as a free element in nature, but as gallium(III) compounds in trace amounts in zinc ores and in bauxite. Atomic Number of Hydrogen = 1 This means that the number of protons in a hydrogen atom, represented by Z , is equal to 1. Promethium is a chemical element with atomic number 61 which means there are 61 protons and 61 electrons in the atomic structure. Europium is one of the least abundant elements in the universe. It is the heaviest essential mineral nutrient. The chemical symbol for Neon is Ne. Tellurium is a chemical element with atomic number 52 which means there are 52 protons and 52 electrons in the atomic structure. 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. Niobium is a chemical element with atomic number 41 which means there are 41 protons and 41 electrons in the atomic structure. Erbium is a silvery-white solid metal when artificially isolated, natural erbium is always found in chemical combination with other elements. Titanium condenser tubes are usually the best technical choice, however titanium is very expensive material. Chromium is a steely-grey, lustrous, hard and brittle metal4 which takes a high polish, resists tarnishing, and has a high melting point. Caesium has physical and chemical properties similar to those of rubidium and potassium. The chemical symbol for Palladium is Pd. the atomic number is one. Copper is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. Major advantage of lead shield is in its compactness due to its higher density. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) stabilizes the free metal somewhat against further oxidation. The chemical symbol for Niobium is Nb. Rhodium is a chemical element with atomic number 45 which means there are 45 protons and 45 electrons in the atomic structure. The chemical symbol for Tellurium is Te. The chemical symbol for Mercury is Hg. Promethium is one of only two such elements that are followed in the periodic table by elements with stable forms. The superscripts 1, 2 and 3 written before H are the atomic masses of the isotopes of hydrogen and the subscript 1 is the atomic number. Silver is a soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. Calcium is a chemical element with atomic number 20 which means there are 20 protons and 20 electrons in the atomic structure. Nickel belongs to the transition metals and is hard and ductile. Atomic number = Number of protons. Being constructed of 1 proton and 1 electron it has no neutrons. Actinium is a soft, silvery-white radioactive metal. It's essential for all life and abundant in the universe, so it's one element you should get to know better. In an uncharged atom, the atomic number is also equal to the number of electrons. Hydrogen – Atomic Number – H 2020-11-21 by Nick Connor Atomic Number of Hydrogen Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 … The most common way of showing the arrangement of electrons in an atom is to draw diagrams like those shown in the diagram. Chlorine is a yellow-green gas at room temperature. Hydrogen is a chemical element with atomic number 1 which means there are 1 protons and 1 electrons in the atomic structure. Mendelevium is a metallic radioactive transuranic element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities. Indium is a chemical element with atomic number 49 which means there are 49 protons and 49 electrons in the atomic structure. A hydrogen like atom (atomic number Z) is in a higher excited state of quantam number n. This excited atom can make a transition to the first excited state by emitting a photon of energy 27.2eV. Xenon is a chemical element with atomic number 54 which means there are 54 protons and 54 electrons in the atomic structure. Element Hydrogen (H), Group 1, Atomic Number 1, s-block, Mass 1.008. The chemical symbol for Beryllium is Be. Its properties are thus intermediate between those of chlorine and iodine. Hydrogen is the most abundant element in the universe. The chemical symbol for Californium is Cf. The chemical symbol for Praseodymium is Pr. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide. The chemical symbol for hydrogen is H. The melting point of hydrogen is 14,025 degrees Kelvin or -258,125 degrees Celsius or degrees Celsius. Astatine is a chemical element with atomic number 85 which means there are 85 protons and 85 electrons in the atomic structure. Hydrogen is also used in various industrial fields such as metalworking and as a coolant in generators in power stations. Lithium is a chemical element with atomic number 3 which means there are 3 protons and 3 electrons in the atomic structure. Francium is the second-least electronegative element, behind only caesium, and is the second rarest naturally occurring element (after astatine). Berkelium is a member of the actinide and transuranium element series. The chemical symbol for Sodium is Na. 1) You may use almost everything for non-commercial and educational use. Being constructed of 1 proton and 1 electron it has no neutrons. Actinium is a chemical element with atomic number 89 which means there are 89 protons and 89 electrons in the atomic structure. The chemical symbol for Bromine is Br. The name of the gas is formed from two Greek words, meaning water and forming, so this is the element which creates water. Gold is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. 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”. The hydrogen atom, symbol H, is formed by a nucleus with one unit of positive charge and one electron. Englisch-Deutsch-Übersetzungen für Hydrogen im Online-Wörterbuch dict.cc (Deutschwörterbuch). Atomic number = Number of protons. Argon is a chemical element with atomic number 18 which means there are 18 protons and 18 electrons in the atomic structure. The chemical symbol for Rhenium is Re. The most common way of showing the arrangement of electrons in an atom is to draw diagrams like those shown in the diagram. It is a lanthanide, a rare earth element, originally found in the gadolinite mine in Ytterby in Sweden. Potassium is a chemical element with atomic number 19 which means there are 19 protons and 19 electrons in the atomic structure. Plutonium is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. Iodine is the least abundant of the stable halogens, being the sixty-first most abundant element. Neon is a colorless, odorless, inert monatomic gas under standard conditions, with about two-thirds the density of air. b. Palladium is a chemical element with atomic number 46 which means there are 46 protons and 46 electrons in the atomic structure. The other significant use of this chemical element is in fossil fuel processing. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. It has the symbol H and atomic number 1. Calculate the number of protons, neutrons and electrons it contains. The chemical symbol for Scandium is Sc. It is the fourth most common element in the Earth’s crust. Crossword Clue The crossword clue Hydrogen's atomic number with 3 letters was last seen on the July 23, 2020.We think the likely answer to this clue is ONE.Below are all possible answers to this clue ordered by its rank. The New York Times Mini Crossword is a mini version for the NYT Crossword and contains fewer clues then the main crossword. In a neutral atom there are as many electrons as protons moving about nucleus. This clue was last seen on New York Times Mini Crossword October 15 2020 Answers In case the clue doesn’t fit or there’s something […] Hydrogen= 1; Helium=2; Lithium=3; Beryllium=4; Boron=5; Carbon=6; Nitogen=7; Oxygen=8; Finding the Atomic Number. By mass, aluminium makes up about 8% of the Earth’s crust; it is the third most abundant element after oxygen and silicon and the most abundant metal in the crust, though it is less common in the mantle below. If necessary, click on Reset Nucleus to see the simulation again. It is also the most corrosion-resistant metal, even at temperatures as high as 2000 °C. Discoverer: Scientists at Dubna, Russia (1964)/Albert Ghiorso et. For example, protium, deuterium, and tritium are three isotopes of H which all have Z= 1 The information contained in this website is for general information purposes only. Atomic hydrogen and nascent hydrogen are two terms used in chemistry to identify the same hydrogen element in different applications. The chemical symbol for Molybdenum is Mo. Cerium is the second element in the lanthanide series. Cerium is also traditionally considered one of the rare-earth elements. The atomic number uniquely identifies a chemical element.It is identical to the charge number of the nucleus. The chemical symbol for Neodymium is Nd. Francium is a highly radioactive metal that decays into astatine, radium, and radon. b. Dysprosium is a chemical element with atomic number 66 which means there are 66 protons and 66 electrons in the atomic structure. Natural boron consists primarily of two stable isotopes, 11B (80.1%) and 10B (19.9%). The chemical symbol for Vanadium is V. Vanadium is a hard, silvery grey, ductile, and malleable transition metal. The chemical symbol for Thorium is Th. The chemical symbol for Mendelevium is Md. Hydrogen is the first element in the periodic tableand has the atomic number one. The chemical symbol for Germanium is Ge. 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. The chemical symbol for Erbium is Er. First, if we know the number of protons in an atom of an element, we can find out the atomic number. Scandium is a chemical element with atomic number 21 which means there are 21 protons and 21 electrons in the atomic structure. Lawrencium is the final member of the actinide series. Antimony is a chemical element with atomic number 51 which means there are 51 protons and 51 electrons in the atomic structure. The chemical symbol for Fermium is Fm. The chemical properties of the atom are determined by the number of protons, in fact, by number and arrangement of electrons. The chemical symbol for Indium is In. Praseodymium is the third member of the lanthanide series and is traditionally considered to be one of the rare-earth metals. In nuclear industry cadmium is commonly used as a thermal neutron absorber due to very high neutron absorption cross-section of 113Cd. Thorium is moderately hard, malleable, and has a high melting point. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs. 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). Hydrogen is the first element in the periodic table and has the atomic number one. Oxygen is a chemical element with atomic number 8 which means there are 8 protons and 8 electrons in the atomic structure. 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. The configuration of these electrons follows from the principles of quantum mechanics. In nuclear reactors, promethium equilibrium exists in power operation. See also: Atomic Number – Does it conserve in a nuclear reaction? a. Nobelium is a chemical element with atomic number 102 which means there are 102 protons and 102 electrons in the atomic structure. Iron is a chemical element with atomic number 26 which means there are 26 protons and 26 electrons in the atomic structure. The chemical symbol for Osmium is Os. Lutetium is a silvery white metal, which resists corrosion in dry air, but not in moist air. The chemical symbol for Holmium is Ho. 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. Being a typical member of the lanthanide series, europium usually assumes the oxidation state +3. The modern periodic system is formed on the basis of atomic number and electronic configuration of the atom but Mendeleev classification is based on atomic weight or mass.