What is Air Properties of Air Air we

What is Air? Properties of Air

Air • we know it exists, • it’s all around us, • we see moving trees, • it fills our lungs • it has substance but can’t be seen • we can’t taste it, but we can feel it.

Air • Air – the air we breathe is made of different gases • colourless, odourless and tasteless, • a gas made mainly of nitrogen (78%), oxygen (21%) and small amounts of carbon dioxide, hydrogen and other gases

What do we know about air? (don’t need to copy down) • Air is matter so it must be made up of molecules and atoms. It interacts with objects because we can see the trees swaying in the breeze. We also know it moves things since we can see the clouds moving in the sky and storms approaching us in the distance. We know that the air must move because it brings us our weather.

Con’t (don’t need to copy) • Air can change temperature - we can feel the temperature of the air against our skin. Sometimes air can smell. It is able to carry the smell of roses to our noses or for that matter an angry skunk, too. We know that hot air rises and that hot air can hold more moisture. We see birds using the air to travel from place to place and we also seeds being blown around by the wind.

Con’t (don’t need to copy) • We know that the air can become quite dirty from dust but also quite polluted. Sometimes we can see the pollution or smell the pollution. We know that air must take up space because we have all blown up a balloon or put air in our bicycle tires.

What are the properties of air? Air exists because: • It has Weight • Air has mass • Air can exert pressure • Air can be compressed • Air has temperature • Air is all around us (takes up space)