So i have a homework question which i cant figure out.(adsbygoogle = window.adsbygoogle || []).push({});

Use the saha equation to determine the fraction of hydrogen atoms that are ionised at the centre of the sun (N_II/N_tot)

T=15.7x10^6K

number density n=6.1x10^31 m^-3

m = mass of electron

the saha equation is

N_(i+1)/Ni = 2*Z_(i+1)/n*Z_i * (2π*m*kT/h^2)^(3/2) * exp(-χ_i/kT)

i get that Z_I=2 and Z_II=1 because we are assuming most of the hydrogen is in the ground state(or is that what im doing wrong)? Ive also tried changing units from J to eV but that doesnt seem to be doing anything.

i think at the end of this im meant to get a fraction or percentage, but i keep getting stupid numbers like to the power of -34. can someone tell me what im doing wrong?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Saha equation to determine fraction of hydrogen atoms ionised

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**