NEED HELP ASAP Which process do scientists think provided Earth with an oxygen-rich atmosphere?

radiometric dating

spontaneous generation

photosynthesis

respiration

Compare these two waves : a. the blue wave has a higher pitch, but the orange wave is louder. b.the blue and orange waves have the same volume, but the blue wave has a higher pitch. c.the blue and orange waves have the same pitch, but the blue wave is louder. d.the orange wave has a higher pitch, but the blue wave is louder.

When electrolyzing copper (ll) chloride, what reaction takes place at the anode? what reaction takes place at the cathode?

Consider this equilibrium: n29) + o2(g) + 2no(c).nitrogen gas and oxygen gas react when placed in a closed container. as the reaction proceeds towards equilibrium, what happens to the rate of thereverse reaction?