Sodium chloride melts at  801°C. On the other hand, ice (solid HCovalent bonds often result in the formation of small collections of better-connected atoms called molecules, which in solids and liquids are bound to other molecules by forces that are often much weaker than the covalent bonds that hold the molecules internally together. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earths.Actinium is a soft, silvery-white radioactive metal. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass.Helium is a chemical element with atomic number 2 which means there are 2 protons and 2 electrons in the atomic structure. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.Fluorine is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. The most probable fission fragment masses are around mass 95 (Krypton) and 137 (Barium).Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant.Tungsten is a rare metal found naturally on Earth almost exclusively in chemical compounds. 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.Argon is the third-most abundant gas in the Earth’s atmosphere, at 0.934% (9340 ppmv). This effect is caused by a decrease in the atomic number density. Chemically, sulfur reacts with all elements except for gold, platinum, iridium, tellurium, and the noble gases.Chlorine is a yellow-green gas at room temperature.

Its melting (777 °C) and boiling (1377 °C) points are lower than those of calcium (842 °C and 1484 °C respectively); barium continues this downward trend in the melting point (727 °C), but not in the boiling point (… It is a noble metal and a member of the platinum group.Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). Strontium Element: Strontium is a chemical element with atomic number 38 and is present in the Group II of the periodic table. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226.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.

Nearly all technetium is produced synthetically, and only minute amounts are found in the Earth’s crust. Actinium gave the name to the actinide series, a group of 15 similar elements between actinium and lawrencium in the periodic table.Thorium metal is silvery and tarnishes black when exposed to air, forming the dioxide. It is fairly soft and slowly tarnishes in air. Organostrontium compounds contain one or more strontium–carbon bonds. The elements in the Group II are called alkaline earth metals and they have two electrons in their outermost s-orbital. 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. Commercially, thallium is produced as a byproduct from refining of heavy metal sulfide ores. The periodic table is a tabular display of the chemical elements organized on the basis of their atomic numbers, electron configurations, and chemical properties. As a result of this expansion, the density of most materials decreases. Like all elements with atomic number over 100, nobelium can only be produced in particle accelerators by bombarding lighter elements with charged particles.Lawrencium is the final member of the actinide series.

All four stable isotopes are incorporated, in roughly the same proportions they are found in nature. The Neutron number is rarely written explicitly in nuclide symbol notation, but appears as a subscript to the right of the element symbol. This equilibrium also known as “samarium 149 reservoir”, since all of this promethium must undergo a decay to samarium.Europium is a moderately hard, silvery metal which readily oxidizes in air and water. Elemental rubidium is highly reactive, with properties similar to those of other alkali metals, including rapid oxidation in air.Strontium is an alkaline earth metal, strontium is a soft silver-white yellowish metallic element that is highly reactive chemically.Yttrium is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a “rare-earth element”.Niobium is a soft, grey, ductile transition metal, often found in the minerals pyrochlore (the main commercial source for niobium) and columbite.Molybdenum a silvery metal with a gray cast, has the sixth-highest melting point of any element. Uranium is weakly radioactive because all isotopes of uranium are unstable, with half-lives varying between 159,200 years and 4.5 billion years.