Convection is of two types: natural and forced. Heated air rising is an example of natural convection. Hot air has a lower density than that of the cooler air in the atmosphere above it and therefore is buoyant; as it rises, however, it loses energy and cools.
Your best good carbs sources are from this healthy carbohydrates list: 1  Raw and lightly steamed vegetables, 2  Legumes, beans, nuts and seeds, 3  High fiber 100% whole grains,4  Raw, whole, fresh fruits, 5  Most low fat dairy.our best good carbs sources are from this healthy carbohydrates list: 1  Raw and lightly steamed vegetables, 2  Legumes, beans, nuts and seeds, 3  High fiber 100% whole grains,
But carbohydrate quality is important; some types of carbohydrate-rich foods are better than others: 1  The healthiest sources of carbohydratesâunprocessed or minimally processed whole grains, vegetables, fruits and beansâpromote good health by delivering vitamins, minerals, fiber, and a host of important phytonutrients.