Electromagnets

• What happens when you place two pieces of wood next to each other?

  Nothing happens
• What happens when you place two pieces of granite next to each other?

  Still nothing
• What happens when two pieces of iron are placed next to each other?

  They attract each other
• Why can magnetic objects attract at long distances?

  They generate magnetic fields that extend invisibly
• What are electricity and magnetism described as?

  Two sides of the same coin
• What transforms electric fields into magnetic fields?

  When an electrically charged object starts moving
• What causes a compass needle to move?

  A current of electrons flowing through a wire
• What generates the geomagnetic field?

  Currents in the earth's outer core
• What is the microscopic behavior of electrons in solids?

  They whizz around in atoms and molecules
• What is the intrinsic property of particles that relates to magnetism?

  Intrinsic magnetic moment
• What is the relationship between particles with electric charge and magnetism?

  They also behave as tiny magnets
• What is the role of protons in an atom's magnetism?

  They have a weaker magnetic effect than electrons
• What generates orbital magnetic fields in atoms?

  Moving electrons around the nucleus
• Why do electrons in filled shells not contribute to an atom's magnetic field?

  Their currents cancel out
• What happens to the magnetic fields of unpaired electrons in a half-filled shell?

  Their tiny magnets point in the same direction
• Which elements are known to be magnetic due to their half-filled outer shells?

  Nickel, Cobalt, Iron, Manganese, Chromium
• Why is chromium not magnetic as a solid despite being a magnetic atom?

  It is anti-ferromagnetic as a material
• What happens when magnetic atoms form a solid?

  They can align their magnetic fields or cancel out
• What determines how magnetic atoms align in a solid?

  Whichever alignment requires less energy
• What is the significance of magnetic domains in materials?

  They can point in different directions
• What can happen if a strong external magnetic field is applied to a material?

  It can unify the magnetic domains
• What is required for an object to be magnetic?

  A unified kingdom of magnetic domains
• What is the relationship between quantum mechanics and magnetism?

  Magnetism is a quantum property amplified to larger sizes
• How can a current generate a magnetic field?

  By running it through any electrical conductor
• What is the connection between electromagnets and special relativity?

  It relates to the speed of light