Most plastics are made from oil or natural gas. One step in making plastics from these resources is called cracking. Cracking is a process that breaks down bigger molecules into smaller ones. In one cracking reaction, ethane breaks down to become ethylene and hydrogen. During this process, thermal energy is absorbed from the surroundings and converted to chemical energy. True or False

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o