There are lots of gases that are heavier than oxygen, including the elements of:
Fluorine, Neon, Chlorine, Argon, Krypton, Xenon, Radon
If you take into account compounds, then there are lots more to add, including:
Ozone, Carbon Dioxide, Carbon Monoxide, Nitrous Oxides, Formaldehyde, Methane, etc.
Chat with our AI personalities