Heterogeneous mixture that contains large particles that can settle out or be filtered

suspension

Elements and compounds are pure substances, they are not mixtures. Colloid and suspension, both are heterogeneous mixtures, however, a suspension  by definition has larger particles than a colloid.  

Explanation:

Heterogeneous mixture is a mixture in which both solute and solvent are present in varying composition.

A solution in which solute particles added are larger in size then due to more mass solute particles will settle down at the bottom of the solvent, is known as a suspension.

For example, mud present added in water is a suspension.  

Therefore, we can conclude that heterogeneous mixture that contains large particles that can settle out or be filtered is known as suspension.

i believe the answer is a.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.