Neodymium is a Block F, Group 3, Period 6 element. The electronic configuration is [Xe]4f⁴6s². In its elemental form neodymium's CAS number is 7440-00-8. The neodymium atom has a radius of 181.4.pm and it's Van der Waals radius is 181.pm. Neodymium is the most abundant of the rare earths after cerium and lanthanum. Neodymium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. Primary applications include lasers, glass coloring and tinting, dielectrics and, most importantly, as the fundamental basis for neodymium-iron-boron permanent magnets. Neodymium has a strong absorption band centered at 580 nm, which is very close to the human eye's maximum level of sensitivity making it useful in protective lenses for welding goggles. It is also used in CRT displays to enhance contrast between reds and greens and highly valued in glass manufacturing for its attractive purple coloring. Neodymium is included in many formulations of barium titanate, used as dielectric coatings and in multi-layer capacitors essential to electronic equipment.

Cerium is a Block F, Group 3, Period 6 element. The electronic configuration is [Xe]4f²6s². In its elemental form cerium's CAS number is 7440-45-1. The cerium atom has a radius of 182.5.pm and it's Van der Waals radius is 181.pm. Cerium is one of the products manufactured and distributed under the tradename AE Rare Earths. Cerium is the most abundant of the rare earths metals. It is characterized chemically by having two valence states , the +3 cerous and +4 ceric states. The ceric state is the only non-trivalent rare earth ion stable in aqueous solutions. It is, therefore, strongly acidic. It is also a strong oxidizer. The cerous state closely resembles the other trivalent rare earths. The numerous commercial applications for cerium include metallurgy, glass and glass polishing, ceramics, catalysts, as the electrolyte for solid oxide fuel cells when doped with yttrium, gadolinium or samarium and in phosphors. In steel manufacturing it is used to remove free oxygen and sulfur by forming stable oxysulfides and by tying up undesirable trace elements, such as lead and antimony. It is considered to be the most efficient glass polishing agent for precision optical polishing. It is also used to decolor glass by keeping iron in its ferrous state. The ability of cerium-doped glass to block out ultra violet light is utilized in the manufacturing of medical glassware and aerospace windows. It is also used to prevent polymers from darkening in sunlight and to suppress discoloration of television glass.  

Terbium is a Block F, Group 3, Period 6 element. The electronic configuration is [Xe]4f⁹6s². In its elemental form terbium's CAS number is 7440-27-9. The terbium atom has a radius of 176.3.pm and it's Van der Waals radius is unknown. Terbium is primarily used in phosphors, particularly in fluorescent lamps and as the high intensity green emitter used in projection televisions, such as the yttrium-aluminum-garnet (Tb:YAG) variety. Terbium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. Terbium responds efficiently in x-ray excitation and is, therefore, used as an x-ray phosphor. Terbium alloys are also used in magneto-optic recording films, such as Tb-Fe-Co. Terbium was first discovered by Carl Mosander in 1843.