which of the following is not paramagnetic?
a)Co3+
b)Se2-
c)Gd (element 64)
d)Ni
e)Gd3+
Which has no unpaired electron(s)?
I'm thinking Gd (element 64).
Co3+
To determine which of the given options is not paramagnetic, we need to understand the concept of paramagnetism first.
Paramagnetism refers to the property of certain materials exhibiting a weak attraction to an external magnetic field. This property arises due to the presence of unpaired electrons within the atoms or ions of the material. These unpaired electrons align themselves with the external magnetic field, causing the material to be attracted to the field.
On the other hand, diamagnetic materials have no unpaired electrons and are not attracted to an external magnetic field.
Now, let's analyze each option to determine which one is not paramagnetic:
a) Co3+: Cobalt (Co) with a 3+ charge has an electronic configuration of [Ar] 3d6. This means it has three unpaired electrons, making it paramagnetic.
b) Se2-: Selenium (Se) with a 2- charge has an electronic configuration of [Ar] 3d10 4s2 4p6. This configuration indicates that all its electrons are paired, making it diamagnetic.
c) Gd (element 64): Gadolinium (Gd) is known to be paramagnetic. It has an electronic configuration of [Xe] 4f7 5d1 6s2, meaning it has unpaired 4f electrons.
d) Ni: Nickel (Ni) has an atomic number of 28 and an electronic configuration of [Ar] 3d8 4s2. It has two unpaired 3d electrons, making it paramagnetic.
e) Gd3+: Gadolinium with a 3+ charge retains its electronic configuration [Xe] 4f7 5d1 6s0. Since there are unpaired 4f electrons, Gd3+ is also paramagnetic.
Based on the analysis, the only option that is not paramagnetic is b) Se2-.