Which of the following statements describe p-waves? select the two correct answers

a. they alternately compress and pull apart the particles in matter.
b. they are the first waves detected after an earthquake.
c. they can only travel through the solid rock inside earth.
d. they are the most destructive earthquake wave

A.They alternately compress and pull apart the particles in matter.

B. They are the first waves detected after an earthquake.

Explanation:

P-waves, also known as a compressional wave is the wave that shakes the ground in the same and opposite direction of the wave i.e. back and forthe motion of the ground. They compress and pull apart the material alternatively. The disturbances due to these waves have small magnitude thus making them non destructive. These waves travel at faster speed as compared to other seismic waves and thus help in detecting the earthquake. These wave can travel through liquid, solid and gases.

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation: