Property of substances with all electrons paired that are weakly repelled by magnetic fields.
Practise Bonding & Molecular Structure All Bonding & Molecular Structure topics
Diamagnetism is a weak repulsion from a magnetic field shown by substances in which all electrons are paired. It arises because an applied field induces a small circulating current in the electron distribution that opposes the field. Diamagnetism is a property of all matter, but it is usually overshadowed by paramagnetism when unpaired electrons are present. Diamagnetic materials have small, negative magnetic susceptibilities. Common examples include most organic compounds, water and many salts of closed-shell ions.
Key ideas: All paired electrons give diamagnetism, so predict it from electron configuration: closed shells such as N2, CO, noble gases, most organic compounds and Zn2+ or Cu+. The effect is tiny and temperature independent. Strong diamagnets include graphite and bismuth, and superconductors expel fields fully (the Meissner effect) which is a far stronger effect.
Common mistakes and connections: Students think diamagnetic materials are not affected by magnetic fields at all, or that they are attracted slightly. They are repelled weakly. Another is forgetting that all substances have a diamagnetic contribution, even paramagnetic ones, though it is overwhelmed. Links to paramagnetism, MO theory and transition metal complexes.
All 10 valence electrons of N2 are paired in bonding orbitals, so nitrogen is weakly repelled by a magnetic field. The interactive lesson shows this as a live animation or chart.
Water and nitrogen gas are diamagnetic because all of their electrons are paired.
Property of substances with all electrons paired that are weakly repelled by magnetic fields.
Diamagnetism is a intermediate topic in Bonding & Molecular Structure. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in Bonding & Molecular Structure first: Antibonding Molecular Orbital, MO Diagram of Homonuclear Diatomics, Paramagnetism of Oxygen.
The next topics in Bonding & Molecular Structure are Paramagnetism and Heteronuclear Diatomic MOs.
Yes. The interactive lesson includes a self-check question on Diamagnetism, and the Bonding & Molecular Structure quiz draws on every topic in this area.
Diamagnetism is topic 64 of 104 in Bonding & Molecular Structure.