Phosphorus
Categories: Book of Chemistry, Book of Meanings
Oxygen
Categories: Book of Chemistry, Book of Meanings
Nitrogen
Categories: Book of Chemistry, Book of Meanings
Carbon
Categories: Book of Chemistry, Book of Meanings
Hydrogen
Categories: Book of Chemistry, Book of Meanings
Atomic Number
Categories: Book of Chemistry, Book of Meanings
Element
Categories: Book of Chemistry, Book of Meanings
Aurora 
Rigel 
Doyen Altair 