The Cell Membrane is what controls what enters and leaves the cell.
Answer:
It is called so because it is applicable on all bodies having mass, and the bodies will be governed by the same law, that is newton's law of gravitation. Thus, as it is applicable universally, it is called as universal law.
Answer:
Absolute pressure of the oil will be 102822.8 Pa
Explanation:
We have given height h = 31 cm = 0.31 m
Acceleration due to gravity 
Specific gravity of oil = 0.600
So density of oil 
We know that absolute pressure is given by
, here 
So absolute pressure will be equal to 
So absolute pressure of the oil will be 102822.8 Pa
the number of neutrons may b 21