Block D and F Elements
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4 months agoContributor-Level 10
8.19 Transition metals have a partially filled d−orbital. Therefore, the electronic configuration of transition elements is (n−1) d1-10 ns0-2 The non-transition elements either do not have a partially filled d−orbital. Therefore, the electronic configuration of non-transition elements is ns1-2 orns2 np1-6.
New answer posted
4 months agoContributor-Level 10
8.18 Transition elements are those elements in which the atoms or ions (in stable oxidation state) contain partially filled d-orbital. These elements in the d-block show a transition of properties between s-block and p-block. Therefore, these are called transition elements. Elements such as Zn, Cd, and Hg cannot be classified as transition elements because these have completely filled d-subshell.
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4 months agoContributor-Level 10
8.17 On moving along the lanthanoid series, the atomic number increases. Also, with the increase in atomic number, the number of electrons in the 4f orbital also increases.
The 4f electrons have a poor shielding effect. Therefore, the effective nuclear charge experienced by the outer electrons increases. Consequently, the force of attraction between the nucleus and valence electrons increases. This results in a decrease in the size of lanthanoids with the increase in the atomic number. This is termed as lanthanoid contraction.
CONSEQUENCES:
1. The properties of second and third transition series are similar in
2. Separation of lanthan
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4 months agoContributor-Level 10
8.16 (i) Vanadate (VO3 -)-Oxidation state of V is +
(ii) Chromate (CrO4 2-)-Oxidation state of Cr is +
(iii) Permanganate (MnO4 -) Oxidation state of Mn is + 7
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4 months agoContributor-Level 10
8.15 For answering this question, we can compare the electronic configuration of standard elements and then write their corresponding oxidation
S. No | Electronic configurations in ground state | Stable oxidation states |
1 | 3d3 Vanadium | +2, +3, +4, +5 |
2 | 3d5 Chromium | +3, +4, +6 |
3 | 3d5 Manganese | +2, +4, +6, +7 |
4 | 3d8 Nickel | +1, +2, +3, +4 |
5 | 3d4 | 3d4 configuration is not stable at ground state |
New answer posted
4 months agoContributor-Level 10
8.14 The elements in the first-half of the transition series exhibit many oxidation states with Mn exhibiting a maximum number of oxidation states (+2 to +7). The stability of +2 oxidation state increases with the increase in atomic number. This happens as more electrons are getting filled in the d-orbital.
However, Sc ( [Ar] 3d14s2) does not show +2 oxidation state, instead, it loses all the three valence electrons to form Sc3+. The +3 oxidation state of Sc is very stable as it attains stable configuration.
For Mn ( [Ar] 3d54s2), +2 oxidation state is very stable because after losing two electrons, it attains stable half-filled str
New answer posted
4 months agoContributor-Level 10
8.13 The oxidation states displayed by the first half of the first row of transition metals are given in the table below.
METALS | Sc ( [Ar] 3d14s2) | Ti ( [Ar] 3d24s2) | V ( [Ar] 3d34s2 ) | Cr ( [Ar] 3d54s1) | Mn ( [Ar] 3d54s2) |
OXIDATION STATES |
| +2 | +2 | +2 | +2 |
+3 | +3 | +3 | +3 | +3 | |
| +4 | +4 | +4 | +4 | |
|
| +5 | +5 | +6 | |
|
|
| +6 | +7 |
Except for Sc, all others metals display +2 oxidation state. This is because as the atomic number increases, the number of electrons in the valence shell increases. +2 oxidation state is attained by the loss of the two 4s electrons by these metals. As the number of electron increases, the possibility of an ion with +2 oxidation state being stable (by attaining half-filled structure) also increases. Finally, Mn2+ ions have half-filled structure and are very stable.
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4 months agoContributor-Level 10
8.12 Electronic configuration of Mn2+ is [Ar]183d5 and Electronic configuration of Fe2+ is [Ar]18 3d6 . It is known that half-filled and fully-filled orbitals are more stable. Therefore, Mn in (+2) state has a half-filled stable configuration, whereas the Fe in +3 oxidation state has partially filled subshells, which are relatively unstable. This is the reason Mn2+ shows resistance to oxidation to Mn3+. Also, Fe2+ has 3d6 configuration and by losing one electron, it attains half- filled stable Hence, Mn2+ compounds more stable than Fe2+ towards oxidation to their +3 state.
Mn+2→
Manganese has the atomic no. 25 and its electronic config
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