Explain the difference between a diamagnetic substance and a paramagnetic substance.

A diamagnetic substance is a material that does not have any net magnetic moment of its own. When an external magnetic field is applied, it creates a magnetic field that opposes the applied field, resulting in a repulsive force. This is known as the Diamagnetic Effect. Examples of diamagnetic substances include copper, gold, and water.

A paramagnetic substance is a material that has unpaired electrons which creates an intrinsic magnetic moment in each atom. When an external magnetic field is applied, these magnetic moments align themselves with the applied field, resulting in an attractive force. However, these magnetic moments are weak and transient, so the attraction is not strong. Examples of paramagnetic substances include aluminum, platinum, and oxygen.

In diamagnetic substances, all electrons are paired, and their spins are opposite, which effectively cancels out their magnetic moments. On the other hand, paramagnetic substances have unpaired electrons with parallel spins, leading to a net magnetic moment.

Diamagnetic substances oppose the applied magnetic field, meaning that they are repelled by it. When exposed to a magnetic field, diamagnetic substances develop an induced magnetic field that is opposite to the applied field, resulting in a repulsive force. In contrast, paramagnetic substances are attracted to an applied magnetic field as their magnetic moments align with the applied field, creating an attractive force.

Magnetic susceptibility is a measure of how much a material is magnetized when an external magnetic field is applied. Diamagnetic materials have a negative magnetic susceptibility, meaning that they have an opposing magnetic field when an external magnetic field is present. Paramagnetic materials, on the other hand, have a positive magnetic susceptibility, meaning that they have an aligning magnetic field when an external magnetic field is present.

The magnetic properties of diamagnetic substances do not change with temperature. In contrast, the magnetic properties of paramagnetic substances are temperature-dependent. Their magnetic susceptibility increases as the temperature decreases, according to Curie's Law. This is because the thermal motion of electrons is reduced, which helps stabilize the alignment of magnetic moments with the applied field. In conclusion, the main differences between diamagnetic and paramagnetic substances lie in their electron configurations, magnetic moment alignments, magnetic susceptibility, and the way they interact with external magnetic fields. Diamagnetic substances have paired electrons, zero net magnetic moments, and repel applied magnetic fields, while paramagnetic substances have unpaired electrons, net magnetic moments, and are attracted to applied magnetic fields.