Water Quiz

At 10 meters below, the atmospheric pressure of the ocean is exactly double that of the surface.

• TRUE

• FALSE

Answer explanation

At 33 feet (10 meters) below the surface, the pressure is twice that of the surface. Most divers must use an oxygen tank, though some can hold their breath and swim to that depth.

Roughly 20 percent of the water humans use is for agriculture.

• TRUE

• FALSE

Answer explanation

More than 70 percent of the water used by humans each year goes to agricultural purposes. This includes raising animals as well as plants.

Rainwater is the purest form of water.

• TRUE

• FALSE

Answer explanation

Rainwater contains small amounts of dissolved minerals, as well as particles of dust and dissolved gases. Distilled water is the purest form.

Water contracts when it freezes.

• TRUE

• FALSE

Answer explanation

Water expands when it freezes. Ice, the solid form of that liquid, is one of the few items that floats as a solid.

Condensation is water that comes from the air.

• TRUE

• FALSE

Answer explanation

Water that forms on the outside of a cold glass or on the inside of a window in winter is liquid water condensing from water vapor in the air. In cold air, water vapor condenses faster than it evaporates.

Water boils more quickly in the mountains than at sea level.

• TRUE

• FALSE