How to determine which step is the slow step in a reaction?

Which statement names the physical property of wood a. wood is softer than coal b. wood does not rust c. wood can rot d. wood can burn

If many scientists conduct the same or similar experiments, and all obtain similar results, a can be written, which is a generally agreed-upon statement that explains and predicts how a natural phenomenon works.

Which statement is true about the model of the electromagnetic spectrum a: it change the frequencies of light. b: it compare wavelengths of light. c: the color of light waves can be changed using the model. d: the intensities of light waves can be decreased using the model.