I need help

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.

An atom of lithium-7 has an equal number of(1) electrons and neutrons(2) electrons and protons(3) positrons and neutrons(4) positrons and protons

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.