posted by HELP!!!!! .
The atmosphere contains about 6.8×1013 moles of ozone. If this amount of ozone gas is
compressed into a thin layer around the globe (the radius of Earth is 6370 km) at STP
(Standard Temperature (0°C) and Pressure (1.0 atm.)), how thick will the layer be in
millimeter? One hundredth of 1 mm of this layer is called a Dobson Unit (DU).