What Air Is

Posted by Khmer Ancestor Wednesday, December 10, 2008


Take a really deep breath. Feel how your chest gets bigger and bigger. Your chest gets bigger because your lungs are filling up with air. You cannot see air, but air is all around you. You can feel it when the wind blows.

Earth’s atmosphere is made of air. An atmosphere is made up of the gases that surround a planet.

WHAT IS AIR?

Air is a mixture of several different gases. The main gases in air are nitrogen, oxygen, and argon. Air also contains smaller amounts of hydrogen, carbon dioxide, water vapor, helium, and other gases. Oxygen is the most important gas for animals. Animals must breathe oxygen in order to live.

Carbon dioxide is the most important gas for plants. Plants use carbon dioxide and sunlight to make food. Plants give off oxygen. Animals turn the oxygen back into carbon dioxide when they breathe.

TAKING AIR WITH YOU

You can go to places where there is no air. There is no air underwater, but you can dive underwater. You can stay underwater a short time just by holding your breath. Air tanks let you stay underwater for a long time. Scuba divers wear tanks on their backs. The tanks are filled with gases that make up air. The divers breathe the gases through hoses.

There is less and less air the higher up you go. People gasp for breath at the tops of tall mountains. Airplanes must carry air. Once the airplane gets up high, air is pumped into the cabin where passengers sit. Astronauts have to take all the air they need with them—there’s no air in space!

3 comments

  1. Anonymous Said,

    ល្អមែន​ប្លុកនេះ ខ្ញុំក៏ជាអ្នកលេងប្លុកដែរ តែខ្ជិល​ធ្វើ​រត់មកធ្វើអាថ្មីវិញ ហេ ហេ

    Posted on December 11, 2008 at 7:14 AM

     
  2. Anonymous Said,

    ភ្លេចប្រាប់ ប្លុកបងឯង​គេអ្នក​អត់មាន ប្លុកដូចបងឯង គេមិនអាចបញ្ចេញមតិបានទេ។ បងគួរកំណត់ឲ្យគេបញ្ចេញមតិបាន សំរាប់គ្នាដែល​គ្មានប្លុកនិងគេ

    Posted on December 11, 2008 at 7:15 AM

     
  3. megat Said,

    your blog very beautiful and more info ,make me excited. Congratulation!!.I come again

    Posted on December 13, 2008 at 12:46 AM

     
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