Well, the high energy and heat found in the photons of sunlight allow plants to make their own food, sustaining them long enough to be eaten by us, or to be eaten by animals about to be eaten by us. Plus we get direct warmth from the sun. These things mean that the sun is what keeps all organisms alive in the first place.
The difference in water concentration across a selectively permeable membrane.
Answer:
A semipermeable membrane is a barrier that will only allow some molecules to pass through while blocking the passage of other molecules. A semipermeable barrier essentially acts as a filter. Different types of semipermeable membranes can block out different sized molecules. A semipermeable membrane can be made out of biological or synthetic material.
Explanation:
Helium, with two protons, will have two electrons. In the chemical classroom, the proton count will always be equivalent to an atom's atomic number. This value will not change unless the nucleus decays or is bombarded (nuclear physics). Figure \(\PageIndex{1}\): The periodic table of the elements.