in attemping to characterized an unkown substance a scientist makes several observations. classify each observation as a physical or chemial property

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

How many moles of kci are produced from 2.50 moles k

Two solids are mixed in a flask and stirred. after a few minutes, the flask becomes cold. which of the following best describes this reaction? a. an exothermic reaction b. a combustion reaction c. an endothermic reaction d. a decomposition reaction