The presence of paired or unpaired electrons affects the chemical and magnetic properties of an
atom or molecule. If the material has unpaired electrons, a magnetic field will align the spins of
these electrons and weakly attract the atom. These materials are said to be paramagnetic. Materials
that have no unpaired electrons and are slightly repelled by a magnetic field are said to be
diamagnetic.
THINGS TO REMEMBER
Protons
Neutrons
Electrons
Atomic Weights and Isotopes
Bohr’s Model of the Hydrogen Atom
Principal Quantum Number
Azimuthal Quantum Number
Magnetic Quantum Number
Spin Quantum Number
Electron Configuration