What is the name of the compound Hg2O7

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.

How air particles exert a pressure on the inside of the balloon

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)