Its head water that the best anwers
The correct answer is A....
Answer:
substances can move from areas of low concentration to areas of high concentration
Explanation:
usually substances move across their concentration gradient which is from high concentration to low concentration. Active transport can allow substances to move against their concentration gradient.
Explanation:
The small number behind each element symbol designates the number of atoms of each element in a chemical formula. If there is no number, it is assumed there is only one of those elements. A large number designates how many units there are of that compound.
