9. The ability of a material to fill the form: 1. Viscosity 2. Plasticity 3. Fluidity 4. Elasticity

The correct answer is 2. Plasticity.<br /><br />Plasticity refers to the ability of a material to undergo a permanent deformation without breaking or cracking. It is the property that allows a material to be molded or shaped into a specific form. This property is essential in various applications, such as in the manufacturing of products like clay, plastic, and metal.<br /><br />Viscosity, on the other hand, is a measure of a fluid's resistance to flow. It describes how thick or thin a fluid is and how easily it flows. Fluidity is the ability of a substance to flow easily, while elasticity refers to the ability of a material to return to its original shape after being deformed.