Answer:
3.0x10²¹ atoms/m².s
Step-by-step explanation:
The diffusive flux is the rate at the diffusion happens and can be calculated by:
J = D*ΔC/e
Where D is the diffusion coefficient, ΔC is the concentration variation and e is the membrane thickness, so:
J = 5x10⁻¹⁰m²/s x (5x10²² - 3.5x10²²)atoms/m³/(2.5x10⁻⁹m)
J = 3.0x10²¹ atoms/m².s