What is one of the physical properties of carbon dioxide?

Carbon dioxide is indeed colorless, which is one of its defining physical properties. This quality allows it to be undetectable by sight in the air, which can lead to safety issues in situations where CO2 accumulates, as people may not realize it is present in high concentrations. This colorlessness is an important characteristic in a variety of applications such as in beverage carbonation, where its lack of color enhances the visual appeal of drinks.

Regarding the other options, carbon dioxide is actually non-flammable, which contradicts the notion of high flammability. It also has no strong odor, making it less detectable without specific instruments. While carbon dioxide exists as a gas at atmospheric conditions, it does not remain a gas at all temperatures; it can change states under varying temperature and pressure conditions, which is why it can be found as a solid (dry ice) under low temperature or high-pressure scenarios. Therefore, the property of being colorless is a significant aspect of carbon dioxide's characteristics.