Inner-transition elements electron configurations

Symbol Lu atomic number 71 atomic weight 174.97 a lanthanide series element an /-block inner-transition metal electron configuration [Xe]4/i45di6s2 valence -1-3 atomic radius (coordination number 12) 1.7349A ionic radius (Lu3+) 0.85A two naturally-occurring isotopes Lu-176 (97.1%) and Lu-175(2.59%) Lu-172 is radioactive with a half-life of 4xl0i° years (beta-emission) several artificial isotopes known, that have mass numbers 155, 156, 167—174, 177—180. 

Symbol Pa atomic number 91 atomic weight 231.04 an actinide series radioactive element an inner-transition metal electron configuration [Rn]5/26di7s2 valence states +4 and +5 atomic radius 1.63A (for coordination number 12) twenty-two isotopes are known in the mass range 215-218,... 

The /block includes all the inner transition elements. Atoms of /block elements have filled s orbitals in the outer energy levels, as well as filled or partially filled 4/and 5/orbitals. In general, the notation for the orbital filling sequence is ns, followed by (n - 2)/, followed by (n - l]d, followed by (for period 6 elements) np. However, there are many exceptions that make it difficult to predict electron configurations. Because there are seven/orbitals, with a maximum of fourteen electrons, the /block spans fourteen groups. 

Symbol Am Atomic Number 95 Atomic Weight 243.0614 an inner-transition, actinide series, radioactive man-made element electron configuration ... 

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%). 

Symbol Lr atomic number 103 atomic weight 262 a transuranium inner-transition actinide series element a synthetic radioactive element electron configuration [RnjTs b/ Sdi valence +3 six isotopes of masses 255 to 260 have been synthesized longest-lived known isotope Lr-260 has half-life of 3 minutes. 

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 ... 

The properties of the elements stem from their electronic configurations, and the properties place them in their locations in the periodic table. In each group, the elements have a characteristic outermost electronic configuration. The existence of the transition and inner transition elements stems from adding electrons to inner shells after outer shells have been started. Because the periodic table reflects the electronic structures of the atoms, it can be used as a memory device when writing electronic configurations. The ability to write and understand such configurations is a very important skill. (Section 4.8)... 

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... 

How do the electron configurations of the transition metals and inner transition elements differ from those of the main group metals ... 

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)... 

General Principles of Electron Configurations Unusual Configurations Transition and Inner Transition Elements... 

Group electron configuration is ns np. Down the group, the number of oxidation states decreases, and the lower (+2) state becomes more common. Down the group, size increases. Because transition and inner transition elements intervene, IE and EN do not decrease smoothly. 

Compare the electron configurations of the main transition elements and the inner transition elements. 

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