Final answer:
In a scale model of the solar system where all sizes and distances are reduced by a factor of one billion, the Earth becomes the size of a grape and the diameter of the Sun becomes the size of a chickpea.
Step-by-step explanation:
In this scale model of the solar system, if we reduce all the sizes and distances by a factor of one billion, the Earth becomes the size of a grape and the diameter of the Sun becomes the size of a chickpea.
According to the information provided, Earth has a diameter of 1.3 centimeters in this model, which is about the size of a grape. The Sun, on the other hand, has a diameter of nearly 1.5 meters, which is about the average height of an adult. Therefore, in the scaled-down version, the Sun would be the size of a chickpea.