Electronic Configuration — Prelims Questions

Which of the following lanthanoids has an electronic configuration with a $5d^1$ electron in its ground state?

Which of the following lanthanoid ions is diamagnetic?

The most stable oxidation state of Europium (Eu, Z=63) is $+3$. However, it also exhibits a stable $+2$ oxidation state. What is the electronic configuration of $Eu^{2+}$?

What is the correct electronic configuration for Cerium (Ce, Z=58)?

Which of the following lanthanoid ions would be expected to be a strong reducing agent due to its electronic configuration?

Which of the following statements regarding the electronic configuration of lanthanoids is incorrect?