Determine the frequency of light (use speed of light) of 8.5 x 10^-7

In as 1°, 2°, 3°, or 4°. be to . : °b: °c: °d: ° : °b: °c: °d: ° : °b: °c: °d: °e: °f: °g: °h: ° : °b: °c: °d: °e: °f: °g: °h: °i: °

Two solids are mixed in a flask and stirred. after a few minutes, the flask becomes cold. which of the following best describes this reaction? a. an exothermic reaction b. a combustion reaction c. an endothermic reaction d. a decomposition reaction

If this sedimentary rock layer is truly the oldest one of marine origin, what do you think that tells usabout the formation of earth's oceans?