Lutetium is element number 71, with the symbol Lu. Its name comes from Lutetia, the old name for Paris. It is the last of the lanthanoids.
Atomic number 71175.0
LuLutetiumルテチウム (rutechiumu)
Symbol
Lu
Atomic weight
175.0
Place in the table
Period 6 · Lanthanoids
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
The old name of Paris
Lutetium was discovered in 1907 and named after the old Latin name for Paris, the capital of France.
Where it sits on the table
The fifteen elements from lanthanum to lutetium are called the lanthanoids. On the Room of the Elements table they are in the upper of the two rows set apart at the bottom.
After lutetium, element 72 is hafnium, in the sixth row of Group 4.
Think about it
Q1Find the elements linked to France (gallium, francium, lutetium) on the table.
Q2Why might a city’s old name be used for an element?
Q3Can you name the first and last lanthanoids?
There is no single right answer. Talking it over with someone at home is a good way to learn.
Did you know? — Three elements are named after old names of capitals: lutetium (Paris), holmium (Stockholm) and hafnium (Copenhagen).