Answer:
Production of liquid oxygen from air Oxygen is generated by liquefaction of atmospheric air in the air separation unit (ASU). Cryogenic technique is the most commonly used for producing liquid oxygen for industrial and medical applications .
Explanation:
its the fourth one
you have to add then round
0ne mole of CuSO4.5H2O contains 6.023×10^23 no.of molecules
Again, 1 mole CuSO4.5H2O contains 9 oxygen atoms
Therefore,1 mole CuSO4.5H2O contains 9 × 6.023×10^23 no.of oxygen atoms
Hope this help!
12 sub levels are in an atom