Lanthanides
The lanthanide series of chemical elements comprises the fifteen metallic chemical elements withatomic numbers 57 through 71, from lanthanum through lutetium . These fifteen lanthanide elements, along with the chemically similar elements scandium and yttrium, are often collectively known as the rare earth elements.
Actinides
The actinide series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.The actinide series derives its name from the first element in the series, actinium.They all have very large atomic andionic radii and exhibit an unusually large range of physical properties. While actinium and the late actinides (from americium onwards) behave similarly to the lanthanides, the elements thorium through neptunium are much more similar to transition metals in their chemistry.
