Which of the following species is NOT isoelectronic with neon?

Conductivity of a solution is $$1.26 \times 10^{-2} \Omega^{-1} \mathrm{~cm}^{-1}$$ Calculate molar conductivity for $$0.01 \mathrm{~M}$$ solution.

Identify the molecule from following that does NOT involve $$\mathrm{sp}^3$$ hybridisation.

Which among the following compounds is hemiacetal?