seawater

Everyday

The salty water of the sea or the ocean. tree →

In the lessons

In science, seawater is salty because it has dissolved salts, mostly sodium chloride (common salt), washed from rocks by rivers over millions of years; about 35 grams of salt in every litre. You cannot drink seawater: it makes you thirstier and is harmful. Salt can be got from seawater by evaporation, which is how sea salt is made. Seawater is denser than fresh water, so it is easier to float in. In safety, seawater has currents and tides; swim between the flags where lifeguards watch. Phrases: "drink seawater", "a bucket of seawater", "seawater evaporates".

Examples

• Never drink seawater; it is too salty. tree →
• We left seawater in a dish and the sun dried it into salt crystals. tree →
• Seawater tastes salty because of dissolved salts. tree →
• It is easier to float in seawater than in a pool. tree →
• The crabs lived in a rock pool of seawater. tree →
• Seawater makes metal rust faster. tree →
• About 97 out of every 100 litres of Earth's water is seawater. tree →
• We filled our bucket with seawater to keep the shells wet. tree →
• It had something of the taste of seawater, certainly, although it had been drawn from the well outside. tree →

Note

Uncountable: some seawater, not "a seawater". Written as one word or two (sea water). "Salt water" and "fresh water" (rivers, lakes, rain) are opposites. Myth: seawater cannot quench thirst; drinking it makes dehydration worse.