How many energy levels in a astatine?

Answer 1

Six electron shells

Answer 2

Astatine has multiple energy levels, but the exact number depends on the context in which you are referring to them. In an atom, astatine can have multiple electron energy levels based on its electron configuration. In a nuclear context, astatine isotopes may have different energy levels related to their nuclear structure and decay modes.

Answer 3

The presumable valence of astatine is -1.