What is the best definition of diffusion?

random movement of molecules across a concentration gradient until the difference in concentration between two regions is near zero

a process in which molecules move across a semipermeable membrane until the number of molecules of water is nearly equal on both sides

net movement of molecules across a permeable membrane bilayer that requires transport proteins

the exchange of solute molecules across a permeable membrane from areas of high concentration to areas of low concentration

The last option : The exchange of solute molecules across a permeable membrane from areas of high concentration to areas of low concentration

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.