An 80 gram sample of a radioisotopes decayed to 40 grams in 3 days how many grams of the original sample would remain after 9 days

Use the drop-down menus to label each of the following changes p for physical change and c for chemical change. the substance changes to a new substance. the original substance can be recovered. the color changes. gas is produced and given off. the substance changes size, shape, or volume.