Gulp.....wouldn't you rather know how big a prominence is...or a sunspot?
Well...OK.
According to Einar Tandberg-Hanssen and A. Gordon Emslie's book The Physics of solar flares published by Cambridge University press in 1988, on page 74 we electrical conductivity of a perfectly ionized gas with no magnetic fields is given by:
3/2
8 T
sigma = 2.37 x 10 ------------
Z ln G
where
3 3 3 1/2
G = ------ ( k T /(pi N) )
3
2 Z e
-1
and the unit of conductivity is seconds
The conductivity, sigma, is just 1/resistivity. To evaluate the above, first
determine the electron density in the sun, Ne, then look up the temperature,T,
and from an average Z of 1.0, compute G. Plug this into the first formula to
get sigma, then take the reciprocal to get the resistivity. From another
reference book: Peter Fox and Ira Bernstein "The Internal Solar Angular
velocity" published by Reidel and COmpany in 1987 and edited by B. Durney and
S. Sofia, on page 215 they state that the 'isotropic milecular electrical
conductivity, sigma, equals 9 x 10^6 T^(3/2) sec^(-1) and they say it is a
function only of radius ( because the temperature and electron density from
the top two formulae depend only on distance from the center) and that sigma
varies from 10^19 sec^(-1) near the core, to 5 x 10^(12) sec^(-1) near the
surface.
I do not have any good references for kinematic viscosity because it is anisotropic. Along the solar magnetic field it is lower than perpendicular to the magnetic field.