_________is a guide to the periodic table and a database of information about chemistry and the elements

__________ is a 3D astronomy program 

___________ is a periodic table application for Linux.

Software used to represent day and night at a given time

_________, a cool little game where kids build molecules out of atoms 

_______ is a desktop environment for Linux based operation system. 

Which of the following is a GTK-based chemical structures drawing program?

__________ is a planetarium program