The activity will explain mechanical stress (the internal forces a material exerts in response to external forces) with stress balls. We will walk students through making stress balls using Orbeez (water filled sodium polyacrylate orbs) and balloons. We will use a table cloth, funnel, and work in trays to prevent making a mess, and use multiple layers of balloons on each stress ball to prevent leaking or exploding. We will then use the stress balls to explain the principles of stress, compression, and tension!