Why does group 18 in the periodic table not form ions?

Lets take a moment to list all the characteristics of the group 18 (also known as noble gases and/or group 8) elements: 
- They have 8 valence electrons. 
- Don't need ANY more electrons because their octet is full (stable). 
- Are stable 
- Not reactive
- Known as the noble gases

Now.. lets take some time to think about why elements want to form ions: 

Elements form ions to either gain or lose valence electrons to the element they bond with. This helps them GAIN a full octet. What is a full octet, you may ask? An octet is when an element has all 8 valence electrons and is stable, making it nonreactive. 

Why would an element with a full octet want to bond? It already has a full octet, it does not need to bond. 

That, my fellow user, is why the noble gases do not need to bond. 

I really do hope this helps! Enjoy, and good luck on the studies.