Question

lanthanum and lutetium do not show colouration in solutions​

Answer 1

Answer:

Lanthanum(La 3+) have 4f ^0 and lutetium (Lu 3+) have 4f^14 configuration. Because of the absence of an unpaired electrons , these ions impart no colour to the solution.

Answer 2

Explanation:

Lanthanum(La 3+) have 4f ^0 and lutetium (Lu 3+) have 4f^14 configuration. Because of the absence of an unpaired electrons , these ions impart no colour to the solution.