Answer:
False.
Step-by-step explanation:
Cell membrane is made of the lipids and proteins with the attached moieties of carbohydrates. The plasma membrane is the selectively permeable membrane that allows the diffusion of some selected particles only.
The transport along the cell membrane depends on the size and the hydrophobicity of the molecule. The size of oxygen is although higher than magnesium but to its highly hydrophobic nature it can easily pass through the plasma membrane as compared with the magnesium. The oxygen diffuses out faster than magnesium.
Thus, the answer is false.