What is the phenomenon in which white phosphorus spontaneously catches fire in air at room temperature due to its low ignition temperature?

💡 Solution & Explanation

Spontaneous combustion occurs when a substance with a low ignition temperature, such as white phosphorus at approximately 303 Kelvin, reacts with oxygen in ambient air and catches fire without an external ignition source. Unlike phosphorescence which involves the emission of light without significant heat, spontaneous combustion rapidly generates thermal energy exceeding the threshold limit. White phosphorus is therefore stored under water to prevent accidental exposure to air.