Which one of the following species is paramagnetic?
Cu+
Ca
Ag+
Cr3+
Zn
Cu+ and Cr3+ are paramagnetic.
To determine which species is paramagnetic, we need to look at their electron configurations. Paramagnetic substances have unpaired electrons, while diamagnetic substances have all of their electrons paired.
Let's analyze the electron configurations of the given species:
Cu+: With the electron configuration [Ar] 3d10, Cu+ has a completely filled d orbital with all electrons paired. Therefore, it is diamagnetic.
Ca: The electron configuration of calcium is [Ar] 4s2. The last two electrons in the 4s orbital are paired, so calcium is diamagnetic.
Ag+: The electron configuration of silver(I) is [Kr] 4d10. The 4d orbital is fully filled in this case, so Ag+ is diamagnetic.
Cr3+: Chromium(III) has the electron configuration [Ar] 3d3 4s2. In this case, three electrons in the 3d orbital are unpaired, making Cr3+ paramagnetic.
Zn: The electron configuration of zinc is [Ar] 3d10 4s2. All electrons in the 3d orbital are paired, making Zn diamagnetic.
From the given species, only Cr3+ is paramagnetic.