1- It depends on the incident angle at which the P-wave hits the liquid. Using snells law, a portion of the energy is converted to an S-Wave, a portion of it ir reflected, but the majority of the energy just disappears ( it is absorbed into the liquid ) since P-waves do not travel through liquids.
2- it spreads out making the sound travel faster than it does in air
3- P-waves move up and down
4- S-waves move side to side
5- P-waves are pressure waves, or longitudinal waves. The motion is in the direction of the wave. These waves travel through solids and liquids.
S-waves are shear waves, or shaking waves. The motion is perpendicular to the wave direction. These waves cannot travel through liquids.
An earthquake produces both P and S waves and by monitoring the arrival (or non-arrival) of P and/or S waves around the Earth we can infer a liquid component to the core.
