What is the correct way to write 1,550,000,000 in scientific notation

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.

Compare and contrast refraction of light and sound will give brainliest

As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit