Chlorine is:

Chlorine is classified as a heavier-than-air gas. This means that when released into the atmosphere, chlorine gas will settle downward rather than rise, which is important for safety considerations in case of a leak. The molecular weight of chlorine is approximately 35.5 g/mol, which is significantly higher than that of air, primarily composed of nitrogen and oxygen with an average molecular weight of around 29 g/mol. Therefore, understanding that chlorine is denser than air reinforces the necessity for adequate ventilation and hazard awareness in environments where chlorine is present. This characteristic is crucial in various industrial applications, ensuring that safety protocols are properly followed to mitigate risks associated with chlorine exposure.