How old are the oldest fossils on earth?

Which statement about sound is not true? a. air particles travel with sound waves. b. sound waves cannot travel through a vacuum. c. sound waves exist even if no one hears them. d. air particles vibrate along the path of a sound wave.

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0

What is the chemical formula for dihydrogen monoxide