Which density of carbon dioxide is higher than that of air? For example

Which density of carbon dioxide is higher than that of air? For example

The density of carbon dioxide is high. If you put a long candle and a short candle in a sealed container for combustion, the short one must go out first. The more obvious the difference between the length of the candle and the length of the candle, the faster you find that because the carbon dioxide produced by the candle combustion is higher than the density of the air, it will sink to the bottom, so when the thickness of carbon dioxide deposition is greater than that of the short candle, the short candle will go out first