which of the following are paramagnetic: O2, O2(-), O2(2-) and why?
To determine which of the given molecules are paramagnetic, we need to consider their electron configurations. Paramagnetic substances have unpaired electrons, while diamagnetic substances have all of their electrons paired.
Let's analyze each of the given molecules:
1. O2 (oxygen gas):
The electron configuration of oxygen is 1s^2 2s^2 2p^4. In its ground state, oxygen has two unpaired electrons (one in each of the p orbitals), making it paramagnetic.
2. O2(-) (the superoxide anion):
The superoxide anion has an extra electron compared to oxygen. Therefore, its electron configuration becomes 1s^2 2s^2 2p^5. In this state, the oxygen atom still has one unpaired electron, making it paramagnetic.
3. O2(2-) (the peroxide anion):
The peroxide anion has two extra electrons compared to oxygen. Thus, its electron configuration becomes 1s^2 2s^2 2p^6, which is the same as that of a neon atom. All the electrons are paired, so it is diamagnetic.
In summary, O2 and O2(-) are paramagnetic because they have unpaired electrons, while O2(2-) is diamagnetic because all the electrons are paired.