Spot the element that is NOT a noble gas

Exercise and reference answers

Questions

1. Items

   1. Helium
   2. Neon
   3. Nitrogen
   4. Argon

   Reason

   Nitrogen is in group 15; the others are noble gases in group 18.

   Odd item

   Nitrogen

2. Items

   1. Krypton
   2. Xenon
   3. Radon
   4. Bromine

   Reason

   Bromine is a halogen in group 17.

   Odd item

   Bromine

3. Items

   1. Hydrogen
   2. Argon
   3. Helium
   4. Neon

   Reason

   Hydrogen has its own special placement, not a noble gas.

   Odd item

   Hydrogen