1 .WHAT  IS THE DIFFERENCE BETWEEN PRESSURE AND ATMOSPHERIC PRESSURE PRESSURE:pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distribution gaunge pressure (also spelled the gage pressure)is the pressure relative to the ambinent pressure. pressure is usually measured in pascal unitsATMOSPHERIC PRESSURE: atmospheric pressure is also called as barometric pressure is the pressure with in the atmosphere of the earth the atmospheric pressure is closely approxiamate by the hydrostratic pressure caused by by the weight of the air above the mesurement point 2. .DOES PLASTIC IS BIODEGRADABLE? HOW LONG IT WILL TAKE TO DECOMPOSE  
no,but some of the plastics are biodegradable ........biodegradable plastics are plastics  that can be decomposed by the action of the living organisms .....usually bacteria
biodegradable plastics take three to six months to decompose fully on the under ground of the earth or decompose fully This is the advantage of the biodegradable plastics But the non bio-degradable plastics takes hundreds and thousands of million years to decay Exactly how long a biodegradable bag takes to break down depends on the various factors like temperature and the amount of the moisture present

IS DEFINED AS FORCE PER UNIT AREA  EXERTED AGAINST THE SURFACE BY THE WEIGHT OF THE AIR COLUMN ABOVE THE SURFACE.

PRESSURE REFERS TO THE  FORCE EXERTED ON A SURFACE.
FORCE AND PRESSURE ARE RELEATED BUT THEY ARE NOT SAME THINDS.2.BIODEGRADABLE PLASTIC ARE VERY RAREALY RECYCLE  AND BIODEGRADABLE  DOES NOT MEAN COMPOSTABLE SO THEY OFTEN UP IN THE LANDFILL.