Many synthetic organic compounds such as plastic polymers, and a few natural ones, contain halogen atoms; these are known as halogenated compounds or organic halides. Chlorine is by far the most abundant of the halogens in seawater, and the only one needed in relatively large amounts (as chloride ions) by humans.
What is the difference between a tsunami and a tidal wave? Although both are sea waves, a tsunami and a tidal wave are two different and unrelated phenomena. A tidal wave is the wave motion of the tides. A tidal wave is a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth.
Tsunamis are  ocean waves caused by large earthquakes and landslides that occur near or under the ocean. Scientists do not use the term tidal wave because these waves are not caused by tides. Tsunami waves are unlike typical ocean waves generated by wind and storms. When tsunamis approach shore, the behave like a very fast moving tide that extends far inland. A rule of thumb is that if you see the tsunami, it is too late to out run it. Most tsunamis do not break like the curling, wind-generated waves popular with surfers.