How much mass does the sun lose through nuclear fusion per second?

1.10^6 kg of mass per second

Explanation:

All energy lost by the sun comes from nuclear fusion.

Sun loses energy at 2.5*10^{19}J per hour, that is 9*10^{22}J/s

To find the mass lost by the sun in liberation of energy you use the famous Einstein's equation:

hence, the sun liberates 1.10^6 kg of mass per second

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

f=ma newton

f=100x2.5=250n