hard water

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Lightning over the outskirts of Oradea, Rom., during the thunderstorm of August 17, 2005.

16 Questions About Earth’s Atmsophere and Weather Answered

Large ocean waves breaking on a stormy day. (wave; sea; whitecaps; storm)

Why Is There Fresh and Salt Water on Earth?

Sunlight shining on leaves. Photosynthesis

What Does Photosynthesis Produce?

Iceberg, Arctic (polar, environment, global warming)

Why Does Water Freeze from the Top Down?

Drinking water is poured into a glass.

Water Fluoridation: Just the Facts

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Drinking water is poured into a glass.

Water Fluoridation: Just the Facts

Aurochs. Bos primigenius. Skeleton. Extinct animal. Skeleton of an Aurochs, an extinct wild ox.

6 Animals We Ate Into Extinction

Periodical Cicada, Adult, Magicicada spp. Requires 17 years to complete development. Nymph splits its skin, and transforms into an adult. Feeds on sap of tree roots. Northern Illinois Brood. This brood is the largest emergence of cicadas anywhere

Why Do Some Cicadas Appear Only Every 17 Years?

Berries and leaves of the bittersweet nightshade (Solanum dulcamara) plant. Poisonous plant

7 of the World’s Deadliest Plants

Cathedrale St.Jean in Lyon, France has a 14th-century astronomical clock that shows religious feast days till the year 2019; Perpetual Calendar

Ten Days That Vanished: The Switch to the Gregorian Calendar

Illustration for Demystified "How Dangerous is Quicksand"

How Deadly Is Quicksand?

Figure 13: A Maxim machine gun, belt-fed and water-cooled, operated by German infantrymen, World War I.

7 Deadliest Weapons in History

hard water: Related Content

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Topics

water softening water heavy water anomalous water soft water ice salinity steam hydrate Do Fish Drink Water?Why Is The Ocean Blue?

Quiz

water glass on white background. (drink; clear; clean water; liquid)

Water and its Varying Forms