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.
Tsunami is a Japanese word with the English translation: harbour wave. In the past, tsunamis have been referred to as tidal waves or seismic sea waves. The term tidal wave is misleading; even though a tsunami's impact upon a coastline is dependent upon the tidal level at the time a tsunami strikes, tsunamis are unrelated to the tides. (Tides result from the gravitational influences of the moon, sun, and planets.) The term seismic sea wave is also misleading.