The theory of planetary accretion suggests that if the Earth is formed in the solar nebula gas, the primordial earth should capture the solar composition atmosphere. At that time, Ne included in the atmosphere voluminously dissolves into the magma ocean. However, the amount of dissolved Ne estimated from the captured atmospheric amount is inconsistent with that of Ne found on the present earth. In this study, we investigated the amount of Ne escaped from a mantle as atmosphere decreases at the time of nebula dissipation that had not been considered before. As a result, we found that a large amount of Ne could be escaped from the primordial earth with nebula dissipation and the amount of Ne remained on the Earth could be less than that of the past study.
