Click Reset. Select the Mystery half-life from the left menu. In this setting, the half-life will be different each time you run the simulation. Run at least three experiments. In each experiment, measure the half-life using the Half-life probe on the graph. (The half-life will be different each time.)

When you have found the half-life, click the camera () icon. Right-click the image, and click Copy. Then paste the image below, and label each image with the half-life.