\(\ce{^227_90Th+}\): \(\ce{^227_90Th+}\)
\(\ce{CO2 + C -> 2 CO}\): \(\ce{CO2 + C -> 2 CO}\)
\(\ce{A\bond{-}B\bond{=}C\bond{#}D}\): \(\ce{A\bond{-}B\bond{=}C\bond{#}D}\)
\[\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}\]: \[\ce{Hg^2+ ->[I-] HgI2 ->[I-] [Hg^{II}I4]^2-}\]