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Several times each day, your body takes in a chemical called hydrogen oxide.
This chemical has the power to eat away solid rock over a period of time. In its frozen state, mighty hydrogen oxide can crack concrete and destroy the cells of plants and animals.
Hydrogen oxide is the chemical name for water. The chemical symbol for water is so familiar that it is a nickname for water: H2O. The H stands for an atom of hydrogen, which is positively charged. The 2 indicates that there are two atoms of hydrogen. The O stands for an atom of oxygen, which is negatively charged. Thus, water consists of a bond between three atoms: two positively (+) charged hydrogen atoms and a negatively (-) charged oxygen atom—H-O-H—no matter whether it is found as a liquid, solid (ice), or gas (water vapor).
Water may seem ordinary, but it has some properties that no other substance has. Water is a supersolvent, so it has the power to dissolve materials like no other substance. To find out more about what water can do, you can test many properties of water right in your own kitchen.
TRY THIS!
Rising Dome
The components of water stick together, thereby forming drops. The ability of the components to stick together (called cohesion) causes water to form a “skin” on its surface. The force holding this “skin” together is called surface tension. With a straw or an eyedropper, put drops of water on a coin, then look for a dome of water rising above the coin. Surface tension keeps the dome intact—up to a point. How many drops can you add before the dome collapses and the water spills?
Breaking the Tension
Soap breaks the surface tension of water. Soap attracts dirt and other particles, helping to make dishes and other items clean. Set a dish of water on a level counter, then carefully place a small paper clip on top of the water’s “skin.” (This will take some practice.) Then try to float a paper clip in a dish of soapy water. Without a “skin,” the soapy water cannot hold up the paper clip.
Supersaturated
Water, our supersolvent, dissolves salt—up to a point. What is this point, and how much salt can water dissolve? Add a teaspoon of salt to a glass of water and stir it in, then look at how the water has changed. Keep adding a teaspoon of salt and stirring until the salt no longer dissolves and the grains of salt fall to the bottom of the glass. After the water has completely evaporated over several days, what is left in the glass?
Human Water Walker!
Can humans walk on water? Not usually, but in 1988 Frenchman Rémy Bricka “ski-walked” across the Atlantic Ocean on water skis that were a little shorter than a compact car. The long skis had the effect of spreading Bricka’s weight over the surface of the water, keeping him from sinking. His watery stroll took two months. ▶
▲ A whirlpool in the ocean is a giant version of water that swirls down a drain. It swirls tighter and tighter, and faster and faster, toward a hole in the center. Whirlpools can draw whole ships toward the bottom of the ocean and then spit them back up. Luckily for us, ocean waves near the shore are too chaotic (disorganized) for whirlpools to form.
▲ The wind creates waves on the ocean’s surface, but other forces are at work below the surface. Ocean currents are strong channels of flowing water caused in part by the meeting of warm and cold water. Warm water rises, and cold water sinks. In this satellite photo, the warm current of the Gulf Stream (red) flows up the eastern coast of the U.S. Cold currents from the Arctic (blue) flow down to meet it.
As people who live in desert areas or who experience droughts know, water is valuable. But everyone should realize that water is a precious commodity—worth saving! ▼
Worth Saving
Toilets may use as much as five gallons per flush. Newer, low-flush toilets use 3.5 gallons. But you may have to flush more often—which does not save any water and may make the situation worse.
