Question

Boojho wants to separate the following materials as combustible and non-combustible. Can you help him? Charcoal, chalk, stone, iron rod, copper coin, straw, cardboard, glass, paper, candle, wood.

Answer 1

The ease with which a flammable substance can be ignited, resulting in fire, combustion, or even an explosion, is known as flammability. Fire testing is used to determine the degree of difficulty necessary to induce a material to burn. To measure flammability, a number of test procedures are used across the world. Construction rules, insurance requirements, fire codes, and other restrictions controlling the use of building materials, as well as the storage and handling of highly flammable chemicals within and outside of structures, as well as in surface and air transportation, employ the ratings obtained.

Complete answer:
A combustible substance is one that can burn (combust) in the presence of air. Combustible materials that ignite quickly at room temperature are known as flammable materials. In other words, a combustible substance takes some effort to ignite, but a flammable material ignites instantly when exposed to flame. The degree of flammability or combustibility in air is primarily determined by the material's volatility, which is linked to its composition-specific vapour pressure, which varies with temperature. By expanding the surface area of the substance, the amount of vapour generated may be increased, resulting in a mist or dust.
Combustibility refers to how readily a material may burst into flame when exposed to fire or combustion. When a substance is utilised for building or storage, this is a crucial quality to consider. It's also crucial in procedures that result in flammable compounds as a by-product. For chemicals that are easily flammable, further precautions are typically necessary. Installation of fire sprinklers or storage away from potential sources of ignition are examples of these precautions. Low-flammability materials may be used in construction where the danger of fire must be minimised, such as apartment buildings, homes, or workplaces.
So,

Combustible	Non-Combustible
Straw, Paper, Charcoal, wood, candle, cardboard	Chalk, Copper coin, Stone, iron rod, Glass

Note:
Non-combustible material — When exposed to fire or heat, a non-combustible material does not ignite, burn, promote combustion, or emit flammable gases in the form in which it is used and at the conditions expected. When a solid material passes any of the two sets of passing criteria given in Section 8 of ASTM E 136 when tested according to the technique described in ASTM E 136, it is termed non-combustible.