# In the preparation of compounds of Xe, Bartlett had taken $O_2^{+} Pt F_6^{-}$ as a base compound. This is because:

$\begin{array}{1 1}Both\; Xe\; and\; O_2\; have\; the\; same\; size \\ Both\; Xe\; and \;O_2\; have\; almost \;the\; same \;ionization \;enthalphy \\ Both \;Xe\; and \;O_2\; are\; gases \\Both\; Xe\; and\; O_2\; have\; the\; same\; electron\; gain\; enthalphy \end{array}$

Answer: Both $Xe$ and $O_2$
He noticed that the first ionization potential of Xenon was lower than that of the Oxygen molecule and made a rough Born-Haber calculation to predict that there might be a stable compound: $Xe_2^{+} Pt F_6^{-}$