which of the following statements about catalysts is true? catalysts are always ionic. catalysts are chemically unchanged at the end of a reaction. catalysts increase the activation energy. catalysts increase the temperature of a chemical reaction

Which substances have the lowest melting points: ionic covalent, or metallic

For each of the following types of reactions, write a general reaction formula in the symbolic form—for example, a + b → ab. single-displacement double-displacement synthesis decomposition

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.