use the density of potassium (d = 0.856g/cm^3) to determine The volume in cubic centimeters of a sample that has a mass of 34.4 ounces

What type of reaction fuels the processes seen here?

What amount of heat is exchanged when 106.2 grams of substance y goes from a liquid at 35 degrees celsius to a solid at the same temperature? melting point of substance y = 35 degrees c; δhvaporization = 3.67 j/mol; δhfusion = 3.30 j/mol. mwsubstance y = 28.22 g/mol. −12.4 j −3.51 x 102 j 1.24 x 101 j 351 j

What is the most common reason for matter changing its state?