Macy has been studying physical and chemical reactions in school. She read about chemical reactions and how energy is either required or released during chemical reactions. Which word describes what type of reaction occurs as a lantern burns brightly? A. physical
B. endothermic
C. nuclear
D. exothermic

Asubstance is held in an open container. its particles move past one another at random speeds but do not leave the container. heat is removed from the system, and the particles slow down. when enough heat is removed, the particles no longer have enough speed to overcome the weak attractive forces between them. when this happens, the substance enters its solid state. the process described above is known as .