Which type of material has the highest surface-to-mass ratio and ignites easily?

The type of material that has the highest surface-to-mass ratio and ignites easily is fine sawdust. This is because fine sawdust consists of very small particles, which provides a larger surface area relative to its overall mass compared to larger pieces of wood, such as logs or branches.

When a material has a high surface-to-mass ratio, it allows for more oxygen to come into contact with the material, facilitating the combustion process. Fine sawdust can quickly absorb heat and catch fire more readily than larger, denser materials due to this increased exposure. The tiny particles can ignite with less energy, promoting rapid combustion, which is essential in fire management and starting fires in both safety and operational contexts.

When considering larger materials like logs, medium-sized branches, or coarse wood chips, their increased mass relative to their surface area means that they require more heat or a more intense ignition source to catch fire, which is why they are less suitable for quick ignition compared to fine sawdust.