Mars has a mass of 642,000,000,000,000,000,000,000 kg. How would scientists express this number in scientific notation? A. 0.64224 kg B. 0.642 x 1024 kg C. 0.642 × 1021 kg D. 6.42 x 1023 kg​

The diagram shows a wave. the quantity shown is the amplitude. this quantity is directly proportional to which of these other quantities? a) energy b) frequency c) period d) wavelength

What practical value did astronomy offer to ancient civilizations?

How can you improve the percent yield of copper in this lab? check all possible strategies that will you do so. measure reactants precisely. stir to the reaction take place. chill the reactants before combining them. wait patiently until the reaction completes. make sure to recover as much copper as possible.