Answer : For a species to be diamagnetic it needs to have no unpaired electrons and for paramagnetic the species needs t have unpaired electrons.
Answer 1) : [tex] C_{2} ^{+2} [/tex]
Electronic configuration of carbon is [tex] 1s^{2}2s^{2} 2p^{2} [/tex]
So, electronic configuration of [tex] C_{2} ^{+2} [/tex] will be [tex] 1s^{2} 2s^{2} [/tex], as it has given its two electrons present in the outermost valence shell.
This molecule of [tex] C_{2} ^{+2} [/tex] will behave as diamagnetic species as there are no unpaired electrons in the orbital.
Answer 2) [tex] Li^{-2} [/tex]
Explanation : The electronic configuration of Lithium is [tex] 1s^{2} 2s^{1} [/tex]
When lithium is in [tex] Li^{-2} [/tex] state it will have electronic configuration as [tex] 1s^{2} 2s^{2} 2p^{1} [/tex]
This shows that Lithium has one electron which is available in 2p orbital, and it is also unpaired.
Therefore, the [tex] Li^{-2} [/tex] species will behave like a paramagnetic substance.
Answer 3) [tex] B_{2}^{-2} [/tex]
Boron has electronic configuration as [tex] 1s^{2} 2s^{2} 2p^{1} [/tex],
So, the excited state of [tex] B_{2}^{-2} [/tex] will be [tex] 1s^{2} 2s^{2} 2p^{3} [/tex],
Here, Boron in excited state has one unpaired electron in 2p orbital rest 2 electrons are paired in the 2p orbital.
This will make [tex] B_{2}^{-2} [/tex] as a paramagnetic substance.
[tex]{\mathbf{C}}_{\mathbf{2}}^{{\mathbf{2 + }}}[/tex] is diamagnetic while [tex]{\mathbf{L}}{{\mathbf{i}}^{{\mathbf{2 - }}}}[/tex] and [tex]{\mathbf{B}}_{\mathbf{2}}^{{\mathbf{2 - }}}[/tex] are paramagnetic in nature.
Further Explanation:
MO diagram:
It is a tool used to describe the chemical bonding formed between different molecules. It is used to predict the bond strength and the electronic transitions that a molecule can undergo.
The property of materials by virtue of which they are weakly attracted by the external applied magnetic field is called paramagnetism. It arises due to the presence of unpaired electrons in the atoms so the atoms with incompletely filled atomic orbitals are paramagnetic. Diamagnetism is a property due to which substances are repelled by external magnetic field. It occurs due to presence of paired electrons present in the atom.
The molecular orbital diagrams of [tex]{\text{C}}_2^{2+}[/tex], [tex]{\text{L}}{{\text{i}}^{2-}}[/tex] and [tex]{\text{B}}_2^{2-}[/tex] are drawn in the attached image. There is no unpaired electron present in the MO diagram of [tex]{\text{C}}_2^{2+}[/tex] and all the electrons are paired up so it is diamagnetic in nature. There is one unpaired electron present in the MO diagram of [tex]{\text{L}}{{\text{i}}^{2-}}[/tex] and therefore it is paramagnetic in nature. Thre are two unpaired electrons present in the MO diagram of [tex]{\text{B}}_2^{2-}[/tex] and therefore it is also paramagnetic in nature.
So [tex]{\text{C}}_2^{2+}[/tex] is diamagnetic in nature whereas [tex]{\text{L}}{{\text{i}}^{2-}}[/tex] and [tex]{\text{B}}_2^{2-}[/tex] are paramagnetic in nature.
Learn more:
1. Which molecule cannot be adequately described by a single Lewis structure/ https://brainly.com/question/6786947
2. Do carbon dioxide and water have the same geometry? https://brainly.com/question/2176581
Answer details:
Grade: High School
Subject: Chemistry
Chapter: Chemical bonding and molecular structure
Keywords: MO diagram, C22+, B22-, Li2-, molecular orbital diagram, paramagnetic, diamagnetic, paramagnetism, diamagnetism, paired electrons, unpaired electrons.
