Question

Which element of the 3d series has the lowest enthalpy of atomisation and why?

Hint:

The enthalpy of atomisation is lower for elements with stable electron configurations, such as copper's \( 3d^{10} \), as less energy is required to break the bonds.

Answer 1

The element of the 3d series with the lowest enthalpy of atomisation is copper (Cu). Copper has a completely filled \( 3d^{10} \) configuration, which makes it highly stable. The stability of the \( 3d^{10} \) configuration reduces the energy required to break the metallic bonds during atomisation, hence lowering the enthalpy of atomisation. In contrast, elements like zinc (Zn) and manganese (Mn) have less stable electron configurations and require more energy to break the bonds during atomisation. 

Thus, copper (Cu) has the lowest enthalpy of atomisation due to the stability provided by its filled \( 3d^{10} \) configuration.