Why does sawdust burn faster than logs. A. Heating it
B. Smaller Particles
C. Increasing the concentration

B. Smaller Particles

Explanation:

We know that the rate of reaction increases with increase in the surface area of reactants.

The reacting particles in the log of wood are embedded inside the wood making only very minimal amount of particles available for reaction. This  ultimately slows down the rate of combustion.

However, in saw dust, there is a greater availability of surface area of reactants hence the sawdust burns faster than logs.

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.