Josh is doing an experiment with water. he starts with a plastic cup of water that has a mass of 12 grams. he places the cup in a sealed container and puts it in the freezer overnight. when he takes the container out of the freezer, he notices that the cup has cracked on its sides and the water is now frozen solid. which sentence best describes what josh discovers about the cup of frozen water? a)the mass of the cup of frozen water is 12 grams which means the mass did not change. b)the mass of the cup of frozen water is greater than 12 grams because it changed to a solid. c)the mass of the cup of frozen water is less than 12 grams because the frozen water is lighter than liquid water. d) the mass of the cup of frozen water is greater than 12 grams because the water expanded in the cup when it froze.

             A) The mass of the cup of frozen water is 12 grams which means the mass did not change.

                        When the cup of water is placed in a sealed container in freezer overnight the mass of the cup along with water will not change because the system is closed as well as the water present in it is not allowed to evaporating as the rate of evaporation decreases on low temperatures.

                         Secondly when he takes out the cup from the container he found that the cup has cracked on its sides. This has happened because when the liquid freezes, it starts to form from top because the ice has lower density and hence floats on surface. When the surface is blocked by ice, the inner liquid when freezes results in volume increases therefore, it cracks the glass.

                          With respect to water it is found then when eater is cooled its density first starts to increases but when it reached around 4 °C it starts forming solid ice which results in the formation of hollow spaces and hence, increases the volume by 9%.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.