- Elements in group 18 have complete outer electron shells on the periodic table of elements
- Helium / neon / argon / krypton / xenon / radon belongs to noble gases family , group 18 on the periodic table
- So, helium, neon, argon, krypton, xenon, and radon have complete outer electron shells

- Helium, neon, argon, krypton, xenon, and radon have complete outer electron shells
- If the outermost electron shell of an atom is complete, then the element of those atoms will not react with other elements easily
- So, helium, neon, argon, krypton, xenon, and radon will not react with other elements easily

So, helium, neon, argon, krypton, xenon, and radon will not react with other elements easily
Q: The noble gases, helium, neon, argon, krypton, xenon, and radon, rarely react with other elements because they
Context:
- If the outermost electron shell of an atom is complete, then the element of those atoms will not react with other elements easily 
- Elements in group 18 have complete outer electron shells on the periodic table of elements 
- Helium / neon / argon / krypton / xenon / radon belongs to noble gases family , group 18 on the periodic table