Chlorobenzene on reaction with NaOH at 623k, 300atm in presence of HCl gives​

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.

Each pair of clay balls represents to planetesimals if each plane test molluscum pound of the same material and is separated by the same distance which pair experiences the greatest gravitational attraction

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )