# Paramagnetic and diamagnetic substances

> A spinning unpaired electron creates a small magnetic field. Paramagnetic substance: has unpaired electrons, so it is attracted to an external magnetic field; its magnetic moment rises with the number of unpaired electrons (most transition-element compounds are paramagnetic). Diamagnetic substance: all electrons paired with opposite spins, magnetic moment zero, repelled by an external field.

> [ar-EG] الـ unpaired electron وهو بيلف حوالين نفسه بيعمل magnetic field صغير. الـ paramagnetic substance فيها unpaired electrons، فبتتجذب للـ external magnetic field، والـ magnetic moment بتاعها بيزيد كل ما عدد الـ unpaired electrons يزيد (ومعظم compounds الـ transition elements كده paramagnetic). أما الـ diamagnetic substance فكل الـ electrons فيها paired بـ opposite spins، والـ magnetic moment بتاعها بصفر، فبتتنافر مع الـ external field. المطلوب: تعرّف الاتنين وتشرح ليه واحدة بتتجذب والتانية بتتنافر.

Part of: Transition Elements (https://yaani.ai/en/learn/chemistry/chem-s3-en.ch1)

## Builds on

- Hund's rule and orbital-box diagrams
- Magnets and magnetic fields

## Common mix-ups

- Paramagnetic means a permanent magnet.: It is only attracted inside an external field. ([ar-EG] لأ، الـ paramagnetic substance مش magnet دايم؛ هي مجرد بتتجذب وهي جوه external magnetic field، ولو شلت الـ field مش هتفضل magnet.)
- Diamagnetic means not affected by a magnet.: It is affected, in the opposite way. A diamagnetic substance has all its electrons paired, so its magnetic moment is zero and it is repelled by an external magnetic field. ([ar-EG] لأ، الـ diamagnetic substance بتتأثر بالـ magnet، لكن بشكل عكسي: بتتنافر مع الـ external magnetic field بدل ما تتجذب له.)
- More electrons means more magnetic.: The total number of electrons is not what counts. Unpaired electrons create the magnetic moment; paired electrons with opposite spins cancel each other. Zinc ($d^{10}$) has many electrons, all paired, so it is diamagnetic. ([ar-EG] لأ، العبرة مش بعدد الـ electrons كله؛ الـ unpaired electrons تحديدًا هما اللي بيعملوا الـ magnetic moment، أما الـ paired electrons بالـ opposite spins فمش بيزوّدوه.)

Source: https://yaani.ai/en/concept/te.magnetic-properties