Two examples of common items that use chemical change

Can someone me with questions 12 and 13 plz.

Remember to use the proper number of significant figures and leading zeros in all calculations.gelatin has a density of 1.27 g/cm³. if you have a blob of gelatin dessert that fills a 2.0 liter bottle, what is its mass? 2540 g2500 g3.9 x 10-43.937x 10-4

This classification of drug typically changes the brain's chemistry and reduces its ability to create its own endorphins.