It should be A because the periodic table starts with Hydrogen in this one is a gas
Answer:
A piece of gold foil was hit with alpha particles, which have a positive charge. Most alpha particles went right through. This showed that the gold atoms were mostly empty space. Some particles had their paths bent at large angles. A few even bounced backward. The only way this would happen was if the atom had a small, heavy region of positive charge inside it.
Answer:
Cell membranes (plasma membranes) help organisms maintain homeostasis by controlling what substances may enter or leave cells.
