It rarely occurs in its elemental state or as pure ore compounds in the Earth’s crust.Bromine is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. 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. Under standard conditions, it is the lightest metal and the lightest solid element. The number of neutrons in an element can be found by subtracting the number of protons from the rounded atomic mass of the element. 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. The biochemical mechanisms of action of lithium appear to be multifactorial and are intercorrelated with the functions of several enzymes, hormones and vitamins, as well as with growth and transforming factors. Like all alkali metals, lithium is highly reactive and flammable, and is stored in mineral oil. In fact their absorption cross-sections are the highest among all stable isotopes.Terbium is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife. Uranium has the highest atomic weight of the primordially occurring elements. In nuclear industry boron is commonly used as a neutron absorber due to the high neutron cross-section of isotope 10B.It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. Its properties are thus intermediate between those of chlorine and iodine.Krypton is a member of group 18 (noble gases) elements. Lithium aluminium hydride (LiAlH 4) Lithium borate (Li 2 B 4 O 7) Lithium carbonate (Li 2 CO 3) Lithium chloride (LiCl) Lithium hydride (LiH) Lithium hydroxide (LiOH) Lithium niobate (LiNbO 3) Lithium tantalate (LiTaO 3) Interesting facts: It accounts for only .0007% of the earth's crust. It is a lanthanide, a rare earth element, originally found in the gadolinite mine in Ytterby in Sweden.Thulium is an easily workable metal with a bright silvery-gray luster. The atomic mass is carried by the atomic nucleus, which occupies only about 10The size and mass of atoms are so small that the use of normal measuring units, while possible, is often inconvenient.

Lithium has an atomic number of 3. 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 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.Technetium is the lightest element whose isotopes are all radioactive; none are stable. It is the fifth most abundant element in Earth’s crust and the third most abundant metal, after iron and aluminium.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.Vanadium is a hard, silvery grey, ductile, and malleable transition metal. Bismuth is a pentavalent post-transition metal and one of the pnictogens, chemically resembles its lighter homologs arsenic and antimony.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.Astatine is the rarest naturally occurring element on the Earth’s crust.

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. Neodymium is not found naturally in metallic form or unmixed with other lanthanides, and it is usually refined for general use.