Which process describes the burning of material without a visible flame?

The burning of material without a visible flame is best described by glowing combustion. This process involves the oxidation of a solid material, typically at elevated temperatures, resulting in the material becoming incandescent or glowing without producing flames. This kind of combustion can be observed in smoldering materials, such as charcoal or wood, where heat is generated from the reaction with air but not enough energy is released to produce visible flames.

Glowing combustion often occurs in scenarios where there is sufficient oxygen present to sustain the reaction, yet the temperature is not high enough for a flame to form. This phenomenon is commonly seen in smoldering fires, which can be particularly dangerous as it may not generate visible signs of fire but can still be a source of significant heat and can contribute to fire spread if not managed properly.

In contrast, flaming combustion is characterized by the presence of visible flames; incomplete combustion results in the production of smoke and other byproducts due to insufficient oxygen; spontaneous combustion refers to combustion that occurs without an external ignition source due to heat buildup within the material.