Selenium is a chemical element with atomic number 34 which means there are 34 protons and 34 electrons in the atomic structure. This can be seen when the atomic radius change in periodic table trend. Selenium is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. Curium is a hard, dense, silvery metal with a relatively high melting point and boiling point for an actinide. The chemical symbol for Palladium is Pd. Major advantage of lead shield is in its compactness due to its higher density. 0. and Gay-Lussac, L.-J. It is a soft, silvery-white alkali metal. It occurs on Earth as the decay product of various heavier elements. Ca, K, Ne, O, P . 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. 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. The chemical symbol for Germanium is Ge. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal. The chemical symbol for Radium is Ra. The chemical symbol for Krypton is Kr. Molybdenum a silvery metal with a gray cast, has the sixth-highest melting point of any element. Cadmium is a soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. 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 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”. Atomic radius is defined as the distance from the center of the nucleus of an atom to the outermost shell of electrons. Consequently, the smallest atom is helium with a radius of 32 pm, while one of the largest is caesium at 225 pm. Gelson Luz is a Mechanical Engineer, expert in welding and passionate about materials. Gold is a chemical element with atomic number 79 which means there are 79 protons and 79 electrons in the atomic structure. The chemical symbol for Iron is Fe. The atomic radius of a chemical element is a measure of the distance out to which the electron cloud extends from the nucleus. Berkelium is a member of the actinide and transuranium element series. Titanium condenser tubes are usually the best technical choice, however titanium is very expensive material. Density is defined as the mass per unit volume. The chemical symbol for Neodymium is Nd. Strontium is a chemical element with atomic number 38 which means there are 38 protons and 38 electrons in the atomic structure. Francium is an alkali metal, that has one valence electron. As there are no physical existence of orbital in atoms, it is difficult to measure the atomic radius. Einem Atom wird ein Atomradius zugeschrieben, mit dem seine räumliche Größe näherungsweise bestimmt werden kann. Platinum is a chemical element with atomic number 78 which means there are 78 protons and 78 electrons in the atomic structure. The chemical symbol for Uranium is U. Significant concentrations of boron occur on the Earth in compounds known as the borate minerals. The chemical symbol for Arsenic is As. The chemical symbol for Thulium is Tm. Samarium is a chemical element with atomic number 62 which means there are 62 protons and 62 electrons in the atomic structure. The chemical symbol for Caesium is Cs. The chemical symbol for Neon is Ne. Yttrium is a chemical element with atomic number 39 which means there are 39 protons and 39 electrons in the atomic structure. Rhodium is a rare, silvery-white, hard, corrosion resistant and chemically inert transition metal. The chemical symbol for Ytterbium is Yb. The chemical symbol for Beryllium is Be. Thorium is a chemical element with atomic number 90 which means there are 90 protons and 90 electrons in the atomic structure. Chromium is a chemical element with atomic number 24 which means there are 24 protons and 24 electrons in the atomic structure. If we include man made elements, the densest so far is Hassium. The chemical symbol for Indium is In. The chemical symbol for Fermium is Fm. Sodium is a soft, silvery-white, highly reactive metal. The chemical symbol for Neptunium is Np. It is fairly soft and slowly tarnishes in air. These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. The chemical symbol for Niobium is Nb. The general trend is that as we move from left to right across a period and as we move up any group the atomic radius decreases. 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. The chemical symbol for Selenium is Se. I got Na, Si, C. Because Carbon is in period 2 it has the smallest atomic radius. Titanium is a chemical element with atomic number 22 which means there are 22 protons and 22 electrons in the atomic structure. 7 years ago. Hassium is a chemical element with symbol Hs and atomic number 108. The chemical symbol for Carbon is C. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. Lithium. Compute the volume of the unit cell for Rhenium. The chemical symbol for Hafnium is Hf. Oxygen. However, this assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. Promethium is one of only two such elements that are followed in the periodic table by elements with stable forms. The atomic radius of Carbon atom is 69pm (covalent radius). Nobelium is the tenth transuranic element and is the penultimate member of the actinide series. As the most electronegative element, it is extremely reactive: almost all other elements, including some noble gases, form compounds with fluorine. Which of the following reason correctly justifies than "Fluorine (72pm) has smaller atomic radius than lithium (152pm) a) Fond Liare in the same group Atomic sizo increases down the group b) T and I are in the same period atomic size increases across the period due to increase in number of shells In nuclear reactors, promethium equilibrium exists in power operation. 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. Francium is the second-least electronegative element, behind only caesium, and is the second rarest naturally occurring element (after astatine). Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. The chemical symbol for Dysprosium is Dy. Xenon is a colorless, dense, odorless noble gas found in the Earth’s atmosphere in trace amounts. asked Jan 10 in Chemistry by MoniKumari (52.0k points) jee main 2020 +3 votes. Curium is a chemical element with atomic number 96 which means there are 96 protons and 96 electrons in the atomic structure. Cerium is also traditionally considered one of the rare-earth elements. The atomic radius of Carbon atom is 69pm (covalent radius). Rhenium is a chemical element with atomic number 75 which means there are 75 protons and 75 electrons in the atomic structure. Argon is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily unreactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. 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). Tellurium is chemically related to selenium and sulfur. Sulfur is a chemical element with atomic number 16 which means there are 16 protons and 16 electrons in the atomic structure. Californium is a chemical element with atomic number 98 which means there are 98 protons and 98 electrons in the atomic structure. It is one of the least reactive chemical elements and is solid under standard conditions. The chemical symbol for Holmium is Ho. Dysprosium is a chemical element with atomic number 66 which means there are 66 protons and 66 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. Its extreme rarity in the Earth’s crust, comparable to that of platinum. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. The chemical symbol for Helium is He. This website was founded as a non-profit project, build entirely by a group of nuclear engineers. Bismuth is a chemical element with atomic number 83 which means there are 83 protons and 83 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. 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. 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