Question

Which neutral atoms have the following electron configurations in either a ground state or excited state? Enter the name or symbol.

[Ar]4s23d3 - I know that this is Vanadium

[Xe]6s24f1 - I thought that this was Lu but it counts it wrong each time! Help please!

Answer 1

#57 (La)Lanthanum=[Xe] 5d1 6s2
#58 (Ce)Cerium=[Xe] 4f1 5d1 6s2
based on what I've read, La is the answer,but for some reason-5d1 is used instead of 4f1.

Answer 2

That's right. Count the electrons and there are 57 but the configuration is not right for La.