Propane is a gas at standard temperature and pressure. However, it can exist in both gaseous and liquid states depending on the conditions it is subjected to.
At room temperature, propane is typically found in its gaseous form, as it has a boiling point of about -42 degrees Celsius (-44 degrees Fahrenheit). This means that under normal atmospheric conditions, propane remains a gas. However, when propane is compressed, it can be stored as a liquid in pressurized containers. This is why you often find propane in tanks used for barbecues or heating.
In summary, propane is generally a gas at normal conditions, but it can become a liquid under high pressure. This dual nature allows it to be used efficiently in various applications.