Which from following compounds has lowest boiling point?

Calculate the radius of an atom of an element in pm if it forms bcc unit cell structure having edge length $4.3 \times 10^{-8} \mathrm{~cm}$.

Identify acidic amino acid from following list represented by three letter symbols.

What is the number of unpaired electrons in f orbitals of lutetium in its +3 oxidation state?