Choose correct statements from the following: (a) Sound waves travel faster in solids than in gases. (b) Sound waves travel fastest through vacuum (c) Sound waves are longitudinal waves (d) Sound waves travel slower in gases than in liquids.

- (a) Sound waves travel faster in solids than in gases: True. The speed of sound is generally highest in solids, followed by liquids, and then gases, because particles are closer together and more strongly interacting in denser media. - (b) Sound waves travel fastest through vacuum: False. Sound waves are mechanical waves and require a material medium (solid, liquid, or gas) to propagate. They cannot travel through a vacuum. - (c) Sound waves are longitudinal waves: True. In gases and liquids, sound waves are longitudinal, meaning the particles oscillate parallel to the direction of wave propagation. In solids, sound waves can be both longitudinal and transverse. The primary form of sound propagation in fluids is longitudinal. - (d) Sound waves travel slower in gases than in liquids: True. Consistent with point (a), sound travels slower in gases than in liquids.