1 The largest school district by enrollment with an election in 2016 is Wake County Public School System with 153,534 K-12 students.  The smallest North Carolina school district among the nation's largest with an election in 2016 is Duplin County Schools with 9,628 K-12 students.
Freon only remains a liquid while under pressure inside your refrigerator's cooling system. The chemical changes to a gas as soon as it contacts the air. This means, when you smell freon in and around your refrigerator, you're also inhaling varying amounts of freon gas. According to the Environmental Protection Agency, freon gas is denser than air and travels very slowly to the upper atmosphere.
The freon in air conditioners (home or car) and refrigerators changes from gas to a liquid and back to a gas, which then repeats. This is a physical change because the freon does not change its chemical makeup, just its state (liquid versus gas). A physical change is easily reversible. So the process can repeat and continue and keep us and our food cool.