Inner transition elements actinides

The three series of elements arising from the filling of the 3d, 4d and 5d shells, and situated in the periodic table following the alkaline earth metals, are commonly described as transition elements , though this term is sometimes also extended to include the lanthanide and actinide (or inner transition) elements. They exhibit a number of characteristic properties which together distinguish them from other groups of elements ... 

Symbol Md atomic number 101 atomic weight (most stable isotope) 257 a man-made radioactive transuranium element an inner-transition element of actinide series electron configuration [Rn]5/i37s2 valence +2, -i-3. Isotopes, half-lives and their decay modes are ... 

Moving across each period the f orbital is progressively filled the 4f orbital is filled for the lanthanides, and the 5f orbital is filled for the actinides. These elements are sometimes referred to as the rare earths, because it was originally difficult to separate and identify these elements. Rare earths are actually not scarce, but the term rare earths is still used for the lanthanides and actinides. A more accurate modern term for these two periods are the inner transition elements. 

Tucked into the periodic table between lanthanum (atomic number 57) and hafnium (atomic number 72) are the lanthanides. In this series of 14 metallic elements, the seven 4/orbitals are progressively filled, as shown in Figure 5.17 (page 185). Following actinium (atomic number 89) is a second series of 14 elements, the actinides, in which the 5f subshell is progressively filled. The lanthanides and actinides together comprise thef-block elements, or inner transition elements. 

Where are the transition and inner transition elements in the periodic table The inner transition elements (lanthanides and actinides) are placed in a special region in the periodic table. Explain the reason for this. 

The rules above gave maximum and minimum oxidation numbers, but those might not be the only oxidation numbers or even the most important oxidation numbers for an element. Elements of the last six groups of the periodic table, for example, may have several oxidation numbers in their compounds, most of which vary from one another in steps of 2. For example, the major oxidation states of chlorine in its compounds are -1, +1, +3, +5, and +7. The transition metals have oxidation numbers that may vary from one another in steps of 1. The inner transition elements mostly form oxidation states of +3, but the first part of the actinide series acts more as transition elements and the elements have maximum oxidation numbers that increase from +4 for Th to +6 for U. These generalizations are not absolute rules, but allow students to make educated guesses about possible compound formation without exhaustive memorization. These possibilities are illustrated in Fig. 14-1. 

The f-block elements comprise two series of inner transition elements which appear, firstly after lanthanum and secondly after actinium, in the Periodic Table. The elements from cerium to lutetium are known as the lanthanides and, because of its chemical similarity to these elements, lanthanum is usually included with them. Scandium and yttrium also show strong chemical similarities to the lanthanides, so that the chemistry of these elements is also often considered in conjunction with that of the lanthanide series. The second series of f-block elements, from thorium to lawrencium, is known as the actinide series and again it is usual to consider actinium together with this series. 

The second series of inner transition elements, the actinides, have atomic numbers ranging from 90 (thorium, Th) to 103 (lawrencium, Lr). All of the actinides are radioactive, and none beyond uranium (92) occur in nature. Like the transition elements, the chemistry of the lanthanides and actinides is unpredictable because of their complex atomic structures. What could be happening at the subatomic level to explain the properties of the inner transition elements In Chapter 7, you ll study an expanded theory of the atom to answer this question. 

The two rows beneath the main body of the periodic table are the lanthanides (atomic numbers 58 to 71) and the actinides (atomic numbers 90 to 103). These two series are called inner transition elements because their last electron occupies inner-level 4/orbitals in the sixth period and the 5/orbitals in the seventh period. As with the d-level transition elements, the energies of sublevels in the inner transition elements are so close that electrons can move back and forth between them. This results in variable oxidation numbers, but the most common oxidation number for all of these elements is 3+. 

The lanthanides and actinides, called the inner transition elements, occupy the/region of the periodic table. Their valence electrons are in s and /orbitals. Inner transition elements exhibit multiple oxidation numbers. 

The inner transition elements are found in the/block of the periodic table. In the lanthanides, electrons of highest energy are in the 4/sublevel. The lanthanides were once called rare earth elements because all of these elements occurred in Earth s crust as earths, an older term for oxides, and seemed to be relatively rare. The highest-energy electrons in the actinides are in the 5/sublevel. You probably won t find these elements among your household chemicals. Their names are unfamiliar except for uranium and plutonium, which are the elements associated with nuclear reactors and weapons. However, many of these elements, especially lanthanides, have important practical uses. 

Figure 9.2 gives electronegativity values for the lanthanides and actinides. Notice that the values for both series of inner transition elements do not vary a great deal. Explain why you might have predicted this on the basis of the electron configurations of these elements. (Chapter 7)... 

Properties of the Transition Elements Other Transition Elements A Variety of Uses Lanthanides and Actinides The Inner Transition Elements MiniLab 8.2 The Ion Gharges of a Transition Element... 

All nuclides with Z > 83 are unstable. Bismuth-209 is the heaviest stable nuclide. Therefore, the largest members of Groups 1A(1), 2A(2), 4A(14), 6A(16), 7A(17), and 8A(18) are radioactive, as are all the actinides (the 5/inner-transition elements) and the elements of the fourth rf-block transition series (Period 7). 

The main transition elements include four series of d-block elements with atomic numbers between 21-30, 39-48, 72-80, and 104-109. The inner transition elements include the f-block (rare earth) elements in the lanthanide series (atomic numbers 57-71) and actinide series (atomic numbers 89-103.) All are metals. 

Inner transition elements include the lanthanide series and actinide series. Elements in these series have incomplete f sublevels. 

These are the inner transition elements, and are also called the Actinides. 

Inner transition elements Elements 58-71 (lanthanides) and 90-103 (actinides), which lie between Groups 2A and 3A of the main group elements and are usually placed at the bottom of the periodic table... 

Below the main body of the periodic table are the inner transition elements consisting of two rows of elements that ate actually parts of the 6th and 7th periods, respectively. The first/orbitals begin to fill with the first of the lanthanides, element number 58 (Figure 3.21). The principal quantum numbers of their/orbitals are 2 less than their period numbers. These are 4/orbitals, of which there are 7 that are filled completely with element number 71. The 4/orbitals are filled in the 6th period. The 5/orbitals are filled with the actinide elements, atomic numbers 90-103. 

The 30 elements of the inner transition elements are divided into two groups and called the actinide and lanthanide series. 

Sometimes, too, chemists include the two rows of elements at the bottom of the periodic table with the transition elements. These two rows, often referred to as the inner-transition elements, have partially filled/subshells in common oxidation states. The elements in the first row are called the lanthanides, or rare earths, and the elements in the second row are called the actinides. Figure 23.1 shows the divisions of the transition elements. The B columns of transition elements, as well as the inner-transition elements, frequently form complex ions and coordination compounds. 

The next element, number 121, might be termed eka-actinium, or perhaps superactinium (because it is followed by 32 rather than 14 inner transition elements), and the following superactinide elements (numbers 122-153, inclusive) might have chemical properties somewhat similar to, but also different from, the actinide elements. 

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