Inner transition elements lanthanides

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. 

Reference has been made already to the existence of a set of inner transition elements, following lanthanum, in which the quantum level being filled is neither the outer quantum level nor the penultimate level, but the next inner. These elements, together with yttrium (a transition metal), were called the rare earths , since they occurred in uncommon mixtures of what were believed to be earths or oxides. With the recognition of their special structure, the elements from lanthanum to lutetium were re-named the lanthanons or lanthanides. They resemble one another very closely, so much so that their separation presented a major problem, since all their compounds are very much alike. They exhibit oxidation state -i-3 and show in this state predominantly ionic characteristics—the ions. 

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 La atomic number 57 atomic weight 138.91 a rare-earth transition metal, precursor to a series of 14 inner-transition elements known as the lanthanide series electron configuration [XejSdiGs oxidation state -i-3 atomic radius 1.879A ionic radius (LaS+) 1.061A electronegativity 1.17 two natural isotopes are La-139 (99.911%) and La-138 (0.089%). 

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. 

Another major classification of the elements in terms of the periodic table is shown in Figure 1.7. Three areas are defined and named the main group elements, the transition elements, and the inner transition elements. The main group elements are the simplest to learn abont, and they will be stndied first. The transition elements inclnde some of the most important elements in onr everyday lives, such as iron, nickel, chrominm, zinc, and copper. The transition elements are often divided into four rows of elements, called the first, second, third, and fourth transition series. The elements of the fourth transition series except for actinium (Ac), and those of the main group elements above 112, are artificial they are not found in nature. The two inner transition series fit into the periodic table in periods 6 and 7, right after lanthanum (La) and actinium (Ac), respectively. The inner transition elements include a few important elements, including uranium and plutonium. The first series of inner transition elements is called the lanthanide series, after lanthanum, the element that precedes... 

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 lanthanides, for which the general symbol Ln is used here, have electron configurations with fis in common and a variable occupation of the 4f level. Classically called the Rare Earths, they are also referred to as the inner-transition elements because the 4f electron build-up takes place in the fourth quantum level, below the 5s, 5p and 6s electrons. As the electronic diversity between the atoms is at some depth the elements are very similar chemically. The small differences in properties arise principally from the... 

The first series of inner transition elements is called the lanthanides because they follow element number 57, lanthanum. The lanthanides consist of the 14 elements from number 58 (cerium, Ce) to number 71 (lutetium, Lu). Because their natural abundance on Earth is less than 0.01 percent, the lanthanides are sometimes called the rare earth elements. AH of the lanthanides have similar properties. 

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... 

The lanthanides constitute a series of 15 inner-transition elements with very similar physico-chemical properties, some of which are summarized in Table 14.1. These Group III metals usually exhibit an... 

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. 

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... 

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