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प्रश्न
Explain the anomalous behaviour of chromium.
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उत्तर
- Chromium (Cr) has atomic number 24.
- Its expected electronic configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d4.
- The 3d orbital is less stable, as it is not half-filled.
- Due to inter-electronic repulsion forces, one 4s electron enters into the 3d orbital. This makes the 4s and 3d orbitals half-filled, which gives extra stability, and the electronic configuration of Cr becomes 1s2 2s2 2p6 3s2 3p6 4s1 3d5.
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संबंधित प्रश्न
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| (i) | (a) `n = 3, l = 2, m_l = -2, m_s = - 1/2` |
| (b) `n = 3, l = 2, m_l = -1, m_s = - 1/2` | |
| (ii) | (a) `n = 3, l = 1, m_l = 1, m_s = + 1/2` |
| (b) `n = 3, l = 2, m_l = 1, m_s = + 1/2` | |
| (iii) | (a) `n = 4, l = 1, m_l = 1, m_s = + 1/2` |
| (b) `n = 3, l = 2, m_l = 1, m_s = + 1/2` | |
| (iv) | (a) `n = 3, l = 2, m_l = +2, m_s = - 1/2` |
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(i) \[\ce{Na^{+}, Mg^{2+}}\]
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| (i) Principal quantum number | (a) orientation of the orbital |
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| Column I | Column II |
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| (iii) \[\ce{Ni^{2+}}\] | (c) [Ar]3d64s0 |
| (iv) \[\ce{Cu}\] | (d) [Ar] 3d54s1 |
| (e) [Ar]3d64s2 |
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