Final answer:
A liquid can ignite and burn if its ambient temperature is below its flashpoint when exposed to an open flame, spark, or heat source which provides the energy required to start combustion.
Step-by-step explanation:
A liquid can burn even if its ambient temperature is lower than its flashpoint if certain conditions are met. These conditions include the presence of an open flame, ignition by a spark or heat source, or direct exposure to sunlight in some cases. The ambient temperature does not need to exceed the flashpoint for a liquid to burn, provided one of these ignition sources is present and the substance is in the right conditions. For example, if the vapor pressure of the liquid is greater than the total ambient pressure, rapid evaporation can occur, leading to a fire even below the flashpoint. Additionally, in a scenario like a pressurized can, heating can increase the pressure to a point where the can ruptures, potentially leading to a fire.
A chemical property listed in an exercise would be flammability, as it describes the ability of a substance to catch fire. The flashpoint of a substance, in particular, is the lowest temperature at which it can vaporize to form an ignitable mixture in air. According to flashpoint categories, certain substances can have a flashpoint below common ambient temperatures. Substances with a flashpoint below 73°F (22.8°C) or between 73°F and 100°F (37.8°C) are particularly susceptible to catching fire even at room temperature under right conditions.