Consider the data below

Temperature (0C) Diffusivity (m2/s)
736 2 x 10-13
782 5 x 10-13
835 1.3 x 10-12
Given this data, determine the activation energy for the diffusion process (units of Joules per atom or molecule) in this material and the pre-exponential factor (use units of m2/s).

The pre-exponential factor is: ???

To determine the pre-exponential factor, we need to find the diffusion constant (D) at a reference temperature. The pre-exponential factor is the diffusion constant at this reference temperature, which is usually taken as a known value.

In this case, let's choose the diffusion constant at 736°C as our reference temperature.

From the given data, at 736°C, the temperature (T) is 736°C and the diffusivity (D) is 2 x 10^-13 m^2/s.

Therefore, the pre-exponential factor is 2 x 10^-13 m^2/s.

So, the pre-exponential factor is 2 x 10^-13 m^2/s.