Metal-metal bonding is more frequent in 4d or 5d series than in 3d-series. This is because of
| A. |
Their greater enthalpy of atomization |
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| B. |
the large size of the orbitals which participates in the metal-metal bond formation |
| C. |
their ability to involve ns and (n–1) d-electrons in the bond formation |
| D. |
the comparable size of 4d and 5d-series elements |