How many elements wide is lanthanide (rare earth)/actinide portion of the periodic table?

How many elements wide is the transition metal portion of the periodic table?

Question

How many elements wide is lanthanide (rare earth)/actinide portion of the periodic table?

How many elements wide is the transition metal portion of the periodic table?

aaronq · Answer

lol why'd you post this under thermodynamics? ...

lanthanides are from Cerium to Lutetium.. Actinides from Thorium to Lawrencium, i'm sure you can count.

Transition metals occupy the middle of the table, they have valence d electrons. The number of electrons that can fit into the d orbitals will give you your answer.