Lei Furnatter, age 14, of Little Rock, Ark., for his question:

DOES AIR HAVE WEIGHT?

Air is a little bit sticky and it resists the motion of objects falling through it. If you drop a piece of paper, it will not fall straight downward because it keeps rubbing against the air. The paper will slide edgeways or sideways between the molecules of air. The faster objects move through the air, the more air resistance they meet.

Although air has no color, no smell and no taste, it is nevertheless just as real as water or land. It surrounds the earth.

You can feel the air when the wind blows and often you can see it even though it is transparent. Because

light rays pass straight through the air, sometimes they appear wavy if we look at them through a patch of warm air surrounded by cold air.

Air definitely has weight. It is this weight that keeps balloons that are lighter than air high above the ground. Air resistance and weight keeps birds and airplanes up in the sky just as water resistance and weight helps a water skier skim on the surface of a lake.

As you walk, you push along the bottom of an ocean of air much as a crab crawls on the bottom of an ocean of water.

Air is a mixture of gases. Water in the form of vapor is mixed with the gases. In addition, the air carries tiny specks of solid matter, such as dust. The water and the solid matter, however, are not considered to be part of the air.

Nitrogen makes up a bit more than 78 percent of dry air, which is almost eight tenths of the total. Oxygen makes up almost 21 percent, or two tenths of the volume of air. The remaining one percent is almost entirely the gas argon with traces of neon, helium, xenon, krypton, hydrogen, ozone, carbon dioxide, nitrous oxide and methane.

Molecules of vapor in the air are smaller than one millionth of a millionth of an inch in size. Here's how that number is written: 0.000000000025 millimeter.

Normally air has about 100,000 solid particles per cubic inch. The sparkling clear air far out to sea may have a dust count that is only 15,000 particles per cubic inch while the smoky air of a city may have more than 5 million particles per cubic inch.

You'll also find particles of salt from the ocean, pollen from plants and tiny living things called microbes floating in the air. Also, particles can settle into the earth's air from outer space. This can come in the form of ashes from meteors that burn upon hitting the atmosphere.

Air, in an ordinary drinking glass weighs about as much as an aspirin tablet.