(a) What does the term paramagnetism mean? (b) How can one determine experimentally whether a substance is paramagnetic? (c) Which of the following ions would you expect to be paramagnetic: O2+ , N22 -, Li2+ , O22 - ? For those ions that are paramagnetic, determine the number of unpaired electrons.

Verified step by step guidance

1. (a) Paramagnetism refers to the phenomenon where a substance is attracted to an external magnetic field due to the presence of unpaired electrons. The unpaired electrons have magnetic moments that align with the magnetic field, causing the substance to be attracted to it.
2. (b) Experimentally, one can determine if a substance is paramagnetic by placing it in a magnetic field. If the substance is attracted to the magnetic field, it is paramagnetic. This is often done using a device called a Gouy balance.
3. (c) To determine if an ion is paramagnetic, we need to look at its electron configuration. If it has unpaired electrons, it is paramagnetic. For O2+, it has two unpaired electrons. N22- has no unpaired electrons, so it is diamagnetic. Li2+ has one unpaired electron, so it is paramagnetic. O22- has no unpaired electrons, so it is diamagnetic.
4. For the paramagnetic ions, O2+ has two unpaired electrons and Li2+ has one unpaired electron. This can be determined by writing out the electron configuration for each ion and looking for unpaired electrons.
5. Remember, the key to identifying paramagnetism is the presence of unpaired electrons. If an ion or atom has unpaired electrons, it will be attracted to a magnetic field and is therefore paramagnetic.

Key Concepts

Paramagnetism

Paramagnetism is a form of magnetism that occurs in materials with unpaired electrons. These unpaired electrons create a net magnetic moment, allowing the substance to be attracted to an external magnetic field. Unlike diamagnetic materials, which have all paired electrons and are weakly repelled by magnetic fields, paramagnetic substances exhibit a stronger response due to the presence of these unpaired electrons.

Experimental Determination of Paramagnetism

To experimentally determine if a substance is paramagnetic, one can use a simple method involving a magnet. If the substance is attracted to the magnet, it indicates the presence of unpaired electrons, confirming paramagnetism. Techniques such as magnetic susceptibility measurements can also quantify the degree of paramagnetism, providing further insight into the electronic structure of the material.

Unpaired Electrons and Ions

The presence of unpaired electrons in ions can be assessed by examining their electron configurations. For example, ions like O2+ and N2- can be analyzed to determine their unpaired electrons. A paramagnetic ion will have one or more unpaired electrons, while a diamagnetic ion will have all electrons paired. This distinction is crucial for predicting the magnetic properties of various ions.