in what periods are lanthanides and actinides?
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1: The lanthanides and actinides are displayed below the rest of the periodic table, but in reality belong in the middle of periods 6 and 7, respectively.
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Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electronic and magnetic properties.
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The rare earth elements are marked with a red outline. Why are all rare earth elements are technically transition elements? Strictly speaking, transition elements are the elements in groups 3 to 12 of the periodic table. The rare earth elements, in their widest sense, are Sc, Y and the lanthanides, La to Lu.
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The actinides are elements 89 to 103 and fill their 5f sublevel progressively. Actinides are typical metals and have properties of both the d-block and the f-block elements, but they are also radioactive.
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They are called the lanthanides because they exhibit similar chemical properties to lanthanum, the first element in the group. Actinides are the 15 elements with atomic numbers from 89 to 103. They are named after the first element in the series, actinium.
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Lanthanoid, also called lanthanide, any of the series of 15 consecutive chemical elements in the periodic table from lanthanum to lutetium (atomic numbers 57–71). With scandium and yttrium, they make up the rare-earth metals.
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General Properties and Reactions of The Actinides. The Actinide series contains elements with atomic numbers 89 to 103 and is the third group in the periodic table. ... Lanthanide and Actinide Series are both referred to as Rare Earth Metals.
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The lanthanides are a group of 15 chemical elements, with atomic numbers 57 through 71. All of these elements have one valence electron in the 5d shell. The elements share properties in common with the first element in the group -- lanthanum. The lanthanides are reactive, silver-colored metals.
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The Actinide series contains elements with atomic numbers 89 to 103 and is the third group in the periodic table. ... Lanthanide and Actinide Series are both referred to as Rare Earth Metals. These elements all have a high diversity in oxidation numbers and all are radioactive.
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['Silvery-white metals that tarnish when exposed to air, forming their oxides.', 'Relatively soft metals. ... ', 'Moving from left to right across the period (increasing atomic number), the radius of each lanthanide 3+ ion steadily decreases. ... ', 'High melting points and boiling points.', 'Very reactive.']
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Pacemaker. Lanthanides and actinides are elements with unfilled f orbitals. Lanthanides are all metals with reactivity similar to group 2 elements. Actinides are all radioactive elements.
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The lanthanides and actinides are groups of elements in the periodic table. They are the elements that are often listed below the main section of the periodic table. There are thirty total elements in the lanthanides and actinides. They are often called the "inner transition metals."
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Lanthanides: Properties and Reactions. The Lanthanides consist of the elements in the f-block of period six in the periodic table. While these metals can be considered transition metals, they have properties that set them apart from the rest of the elements.
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lanthanide: The lanthanides are the 14 elements from cerium (atomic number 58) to lutetium (atomic number 71). -block: In the periodic table, any element that has atoms or ions who have valence electrons in f-orbitals.
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['thorium.', 'protactinium.', 'radium.', 'radon.', 'polonium.', 'bismuth.', 'lead.']
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The regular decrease in the size of the lanthanides due to the poor shielding of 4f orbitals because of the diffused shape is known as lanthanide contraction. Similarly , the regular decrease in the size of the actinides due to poor sheilding of 5f orbitals is known as the actinide contraction.
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lanthanide series, a series of metallic elements, included in the rare-earth metals , in Group 3 of the periodic table . Members of the series are often called lanthanides, although lanthanum (atomic number 57) is not always considered a member of the series.