For a pre-event meal, rich sources of carbohydrates, such as bagels, muffins, and bread, should be eaten two to four hours before an endurance event. Eating a calorie dense meal 2 to 4 hours before an endurance event or smaller meals between 2 to 5 hours before, is absolutely essential for topping of muscle glycogen levels as well as providing blood glucose for the intense activity ahead.
When the diffrence is small like between Oxygen and Carbon the electrons will be shared. When it is large like in Na and Cl the Cl will steal one electron.