Nitrogen from a gaseous phase is to be diffused into pure iron at 700°c. if the surface concentration is maintained at 0.26 wt% n, what will be the concentration (in weight percent) 2.8 mm from the surface after 6.3 h? the diffusion coefficient for nitrogen in iron at 700°c is 2.2 × 10-10 m2/s.

Explanation:

Given details

concentration of surface is Cs 0.26 wt%

distance from surface is x 2.8 mm

time t = 3.6 h

original concentration is Co 0

we know that

FROM TABLE OF ERROR FUNCTION WE HAVE

Z           erf(z)

0.60        0.6039

0.65         0.6420

so by interpolation technique we have

for z = 0.626 we have value of erf(0.626) =   0.623

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8

12 is it do you think so