Once equilibrium is reached, roughly equal numbers of molecules move in either direction across a semipermeable membrane, and there is no further change in concentration on either side of the membrane.
true or false

true

Explanation:

When the number or molecules or concentration of substance is equal inside and outside the cell, the state of equilibrium occurs. Equilibrium is a state of balance in which concentration of molecules are equal on both sides of medium or container or cell. If concentration of substances is higher inside the cell so diffusion occurs until concentration becomes equal on both sides i. e. inside the cell and outside the cell.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.