Final answer:
Charcoal starter cubes are an example of a flammable solid, designed to easily catch fire for the purpose of igniting grills or fires.
Step-by-step explanation:
Charcoal starter cubes are an example of a flammable solid. These are substances that are solids rather than liquids or gases and can easily catch fire and burn in air. The term "oxidizing" refers to chemicals which contain oxygen that may cause other materials to combust, such as potassium dichromate, but charcoal starter cubes do not fall under this category. Instead, they are specifically designed to ignite easily and facilitate the burning process when starting a grill or a fire. They are not flammable liquids, since they are not in liquid form; nor are they dangerously reactive materials, as they do not react violently under normal conditions.