Fact 1: Plasma is formed by electrons separating from atoms in stars.

Fact 2: Color can be seen in some bright astronomical objects, such as stars, and bright planetary nebulae.

Given the two facts above, answer the question "Electrons separating from what in certain bright astronomical objects forms plasma?" with the following options: 
- flames
 - iron
 - Energy.
 - atoms
 - matter
 - energy
 - quarks
 - rocks


 

    atoms     