Answer:When you pass a mixture of iron, salt, and water through a screen, the materials separate based on their physical properties:1. Iron: Since iron is a solid with larger particles compared to the screen's mesh size, it will stay on top of the screen.2. Salt and Water: Both salt (in solution) and water are small enough to pass through the screen. In the case of salt dissolved in water, the salt is dissolved and forms a solution, so it will pass through with the water.In summary:- Stays on top:Iron- Passes through: Salt (dissolved) and water