What are the properties of a liquid? Material processes - Solids, liquids and gases - Liquids Learning Points Liquids do not have a fixed shape. The speed at which a liquid flows is known as viscosity. Liquids have fixed volume. The molecules in a liquid are close together but allow some movement. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.