Assuming (2s-2p) mixing is not operative, the paramagnetic species among the following is:

• (A) Be₂
• (B) B₂
• (C) C₂
• (D) N₂

To determine which of the given species is paramagnetic, we need to look at their electron configurations and the presence of unpaired electrons.

Understanding Paramagnetism

Paramagnetic substances have one or more unpaired electrons, which allow them to be attracted to a magnetic field. In contrast, diamagnetic substances have all electrons paired and are not attracted to a magnetic field.

Analysis of Each Species

• Be₂: This molecule has all paired electrons, making it diamagnetic.
• B₂: The electron configuration shows two unpaired electrons, indicating it is paramagnetic.
• C₂: All electrons are paired in this molecule, so it is diamagnetic.
• N₂: This molecule also has all paired electrons, classifying it as diamagnetic.

Final Answer

Among the options provided, B₂ is the paramagnetic species due to the presence of unpaired electrons.