TermMeaningTransverse waveOscillations where particles are displaced perpendicular to the wave direction.Longitudinal waveOscillations where particles are displaced parallel to the wave direction
no, it not useless. we still learn Bohr's model in HS n dats almost 200 yr old! while there may be new models, previous one is good for explaining the basics. it is also useful to learn previous model n see how our understanding improves over time.