A spring scale shows a net force of 0.8 N acting on a 1.5-kg mass. What happens to the acceleration of the object if the net force is decreased to 0.2 N?

The acceleration of the object would decrease. The acceleration of an object is determined by the net force acting on it divided by its mass. In this case, the net force is decreasing from 0.8 N to 0.2 N, so the acceleration of the object would decrease accordingly.