Is Elixir's module an atom?

Question

I'm trying to get to know what modules are in Elixir. Because in Erlang they're just atoms, but in Elixir atoms start with : character. So I've checked these expressions in iex:

iex(16)> is_atom(List) 
true
iex(17)> is_atom(:List)
true
iex(18)> List == :List
false
iex(19)> a = List
List
iex(20)> b = :List
:List

So it's pretty clear that both List and :List are atoms. However, how does it work on Erlang interop layer? Because Erlang's ok is equal to Elixir's :ok.
So which one of these two (List and :List) is equal to 'List' in Erlang?

Answer 1

Interactive Elixir (1.0.4) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> List == :List
false
iex(2)> List == :'Elixir.List'
true

All uppercase atoms in Elixir automatically receive the Elixir. prefix.