An engine is running by burning coal. Which statement is correct? The engine created energy to perform work.
The coal created energy to operate the engine.
The source of energy was created by the sun.
The energy used to perform work can be traced back to the sun.

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

Which common material is an example of a polymer? (25 pts) a. steel b. plastic c. petroleum d. rubbing alcohol

Which fact represents evidence for the big bang theory?