hydrogen molecules diatomic or mono?

I'm using the Sackur Tetrode equation for entropy of an ideal gas (approximating) so that I can differentiate w.r.t. N (and multiply by -T) to get the chemical potential of an ideal gas. However, not just any ideal gas, but the hydrogen in the sun. So one thing I need to know, because I'm pretty sure it will matter in my final answer for the chemical potential, is if hydrogen gas in the sun in monoatomic or diatomic. I'm pretty sure it is diatomic but im not positive...

Extra points if you can tell me whether or not it will matter in my final answer for the chemical potential if it is diatomic or not. thanks