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The cause of the d-block contraction is the poor shielding of the nuclear charge by the electrons in the d orbitals. The outer valence electrons are more strongly attracted by the nucleus causing the observed increase in ionization potentials. The d-block contraction can be compared to the
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of gallium is higher than that of aluminium, whereas the trend in the group would be for it to be lower. The second table below shows the trend in the sum of the first three ionization potentials for the elements
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The d block contraction, also known as the
Scandide Contraction, describes the atomic radius trend that the d block elements (Transition metals) experience.
191:. Their electronic configurations include completely filled d orbitals (d). The d-block contraction is best illustrated by comparing some properties of the
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Other effects of the d-block contraction are that the Ga ion is smaller than expected, being closer in size to Al. Care must be taken in interpreting the
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Gallium can be seen to be anomalous. The most obvious effect is that the sum of the first three
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673:"Lanthanide Contraction- D Block Contraction (Scandide Contraction)"
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16:Reason behind some elements' Anomalous behaviour
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415:, this sequence shows a smooth reduction.
167:4 elements. The elements in question are
109:Learn how and when to remove this message
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679:. Chemistry Libretexts. August 22, 2020
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407:have three valence electrons above a
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195:to highlight the effect on gallium.
47:adding citations to reliable sources
411:electron core. In contrast to the
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34:needs additional citations for
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147:, especially for Ga and Ge
705:Chemistry of the Elements
703:; Earnshaw, Alan (1997).
638:Effective nuclear charge
424:Atomic electron config.
204:Atomic electron config.
653:Lanthanide contraction
643:Electron configuration
611:lanthanide contraction
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709:Butterworth-Heinemann
701:Greenwood, Norman N.
592:ionization potentials
372:ionization potentials
145:"d-block contraction"
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58:"D-block contraction"
648:Exchange interaction
157:scandide contraction
43:improve this article
677:chem.libretexts.org
153:d-block contraction
128:of elements of the
440:M electron config.
220:M electron config.
155:(sometimes called
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718:978-0-08-037941-8
633:Electron affinity
628:Electronegativity
604:inert-pair effect
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413:group 13 elements
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60: –
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54:Find sources:
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32:This article
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681:. Retrieved
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41:Please help
36:verification
33:
683:December 6,
571:] 5d 6s
543:] 4d 5s
515:] 3d 4s
487:] 3s 3p
460:] 2s 2p
361:] 4f 5d
267:] 3s 3p
240:] 2s 2p
730:Categories
659:References
69:newspapers
562:Lanthanum
478:Aluminium
409:noble gas
258:Aluminium
173:germanium
617:See also
600:thallium
506:Scandium
342:Thallium
333:] 4d
305:] 3d
181:selenium
161:orbitals
534:Yttrium
421:Element
286:Gallium
201:Element
189:krypton
185:bromine
177:arsenic
169:gallium
163:on the
83:scholar
715:
596:indium
584:103.2
574:3455.4
518:4256.7
463:6887.4
403:, and
391:, and
354:5438.4
314:Indium
298:5521.1
243:6887.4
187:, and
165:period
130:groups
85:
78:
71:
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528:74.5
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451:Boron
364:88.5
357:[
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280:53.5
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263:[
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231:Boron
90:JSTOR
76:books
713:ISBN
685:2020
598:and
594:for
564:, La
546:3760
508:, Sc
490:5139
480:, Al
429:I.Ps
344:, Tl
326:5083
316:, In
288:, Ga
270:5139
260:, Al
209:I.Ps
151:The
139:and
62:news
556:90
536:, Y
453:, B
436:mol
336:80
308:62
233:, B
216:mol
45:by
732::
711:.
687:.
675:.
579:Xe
569:Xe
551:Kr
541:Kr
523:Ar
513:Ar
495:Ne
485:Ne
468:He
458:He
432:kJ
405:La
399:,
397:Sc
395:.
393:La
387:,
385:Sc
383:,
381:Al
379:,
359:Xe
349:Xe
331:Kr
321:Kr
303:Ar
293:Ar
275:Ne
265:Ne
248:He
238:He
212:kJ
183:,
179:,
175:,
171:,
141:14
137:13
135:,
721:.
434:/
401:Y
389:Y
377:B
214:/
133:2
112:)
106:(
101:)
97:(
87:·
80:·
73:·
66:·
39:.
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