The transition metals may be subdivided according to the electronic structures of their atoms into three main transition series, called the first, second, and third transition series, and two inner transition series, called the lanthanoids and the actinoids. Without exception, the elements of the main transition series (i.e., excluding the lanthanoids and actinoids as specified below) form stable compounds in two or more formal oxidation states. Third, most of these elements dissolve in mineral acids, although a few, such as platinum, silver, and gold, are called “noble”-that is, are unaffected by simple (nonoxidizing) acids. Second, the transition metals form many useful alloys, with one another and with other metallic elements. Many of the elements are technologically important: titanium, iron, nickel, and copper, for example, are used structurally and in electrical technology. The range in these properties is considerable therefore the statements are comparative with the general properties of all the other elements. The most striking similarities shared by the 24 elements in question are that they are all metals and that most of them are hard, strong, and lustrous, have high melting and boiling points, and are good conductors of heat and electricity. Specifically, they form Groups 3 (IIIb) through 12 (IIb). They occupy the middle portions of the long periods of the periodic table of elements between the groups on the left-hand side and the groups on the right. While the term transition has no particular chemical significance, it is a convenient name by which to distinguish the similarity of the atomic structures and resulting properties of the elements so designated. Transition metal, any of various chemical elements that have valence electrons-i.e., electrons that can participate in the formation of chemical bonds-in two shells instead of only one. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.These example sentences are selected automatically from various online news sources to reflect current usage of the word 'atom.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. 2022 At just a single atom thick, graphene is a near-perfect conductor of electricity and can charge much more quickly and last much longer compared to regular lithium-ion batteries. 2022 The record was set by the edge of a graphene sheet, meaning the gate is only a single carbon atom across. 2023 This means an electron can belong to more than one atom at the same time. Will Sullivan, Smithsonian Magazine, 9 Feb. 2022 The new rocket would harness the power of nuclear fission, in which a rapidly moving neutron crashes into an atom, splitting it into two smaller atoms and releasing large amounts of energy. Harper's Bazaar Staff, Harper's BAZAAR, 31 Aug. 2022 The clay mask that could be credited with starting out modern masking craze, this tingling mud formula sucks every atom of gunk out of your pores. Sanjana Curtis, Scientific American, 12 Dec. 2023 This process continues today and accounts for all the elements from helium on the light end, with two protons per atom, all the way up to iron, which has 26 protons in its atomic nucleus. 2023 At the same conference, Andrew Stern and Dennis Selkoe presented the first images that illustrate in detail-down to the individual atom-exactly what lecanemab sticks to in the human brain, and, perhaps, how scientists can improve upon this advance. Recent Examples on the Web This happened despite the fact that the Bob atom always started out in its ground state.
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