See explanation below.
Work Step by Step
a.Paramagnetic substance is attracted to magnetic field, whereas a diamagnetic substance is repelled by magnetic field. b.Transition elements ions have unfilled d-orbitals whose unpaired electrons make the ions paramagnetic.But ions of main group elements have a noble gas configuration with no partially filled levels. When orbitals are filled, electrons are paired which makes the ion diamagnetic. c.The d-orbitals in the transition element ions are partially filled, which allows an electron from a lower energy d-orbital to move to a higher energy d-orbital.All orbitals in the main group element ions are filled, which allows an electron to move to higher energy level, which require highly fair amount of energy and lies outside the visible range of wavelengths.