Define what crystallinity means in a polymer and why it occurs

Amass of 1.5 kg of air at 120 kpa and 24°c is contained in a gas-tight, frictionless piston-cylinder device. the air is now compressed to a final pressure of 720 kpa. during the process, heat is transferred from the air such that the temperature inside the cylinder remains constant. calculate the boundary work input during this process.

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false