COMPOSITION OF THE ATMOSPHERE
We sometimes take the air we breathe for granted.
Ever since our first breathe we have continuously taken oxygen out the
air, without thinking how oxygen got there. Our body creates carbon
dioxide, which we exhale and that gas is added into the atmosphere.
Each one of us is changing the atmosphere.
In ancient civilizations, people could not
understand the origin of many substances. Wind could be gentle as
it brought a cooling effect, but could be devastating in a storm. Wind
seems to come from outer space, but is invisible. You can feel and hear
it, but you canít see it. Air as a mixture of gases, was not really
understood until the late 1700's.
It took a few scientists to discovered the
composition of air. Joseph Black in the mid 1700's discovered
"fixed air," or what we call carbon dioxide. He described the
gas that was released from magnesium carbonate. As he learned the
properties of carbon dioxide, he could then isolate it in air.