Why can xenon expand its octet to form compounds but neon can't

Answer is: xenon has empty d orbitals (5d), d orbitals may accept electrons. Neon does not have empty d orbitals.

For example, xenon hexafluoride (XeF₆) is a compound where xenon uses d orbitals to expand its octet.

1) Neon (symbol: Ne) is an element (noble gas) with atomic number 10, which means it has 10 protons and 10 electrons.

Electron configuration of neon atom: ₁₀Ne 1s²2s²2p⁶.

2) Xenon (symbol: Xe) is an element (noble gas) with atomic number 54, which means it has 54 protons and 54 electrons.

Electron configuration of xenon atom:

₅₄Xe 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶.