The difference between protons and neutrons are that one has a positive charge and one has a neutral charge. The similarities between the two is that they both make up an atom. The Electrons in an atom are in orbit of the cell inside the Electron cloud and is kept in the cloud by electromagnetic force.
You must pack food that has high concentrations of fat and protein. Food like granola bars and canned meat are a good source of energy and heat. This is because the body breaks this food down easily converting it into usable energy. Though some people would suggest that you pack food that are high in carbohydrates, fats and proteins are long-term sources of energy that you would need for your hiking trip.
Answer:
I believe it's <em>size</em>