Why does helium in the spectrum of the Sun give very weak lines, although there is a lot of it on the Sun
September 22, 2020 | Education
| Why does helium in the spectrum of the Sun give very weak lines, although there is a lot of it on the Sun (about 20% of the mass of the main element – hydrogen)?
For the transition of a helium atom to the next level after the ground level, an energy of up to 20 eV is needed, which corresponds to a temperature of 180,000 K. At a solar surface temperature of about 6000 K, a relatively small number of particles have such energy.
