How were the hydrogen compounds necessary for Earth's oceans and early atmosphere primarily delivered?

Answer

Via late impacts from comets or asteroids perturbed from the outer disk.

While volatiles could not condense in the hot inner system, the materials needed for Earth’s oceans and atmosphere were delivered later through gravitational scattering and impacts originating from the icy region beyond the frost line.

How were the hydrogen compounds necessary for Earth's oceans and early atmosphere primarily delivered?
Spaceastronomycompositionsolar systemformationcomponentssolar nebulaPlanetary Formation