Question

Which of the following is NOT a noble gas?
1. Argon
2. Boron
3. Krypton
4. Neon

Answer 1

Correct Answer - Option 2 : Boron

The correct answer is Boron.

• Boron is not a noble gas.

• The noble gases, also known as inert gases and aerogens.
• The elements that belong to group 18 of the modern periodic table.
• The elements that belong to this group are 
  • Helium (He)
  • Neon (Ne)
  • Argon (Ar)
  • Krypton (Kr)
  • Xenon (Xe)
  • Radon (Rn)
• Under standard conditions for temperature and pressure, all the noble gases exist in the gaseous phase.
• They are known to possess extremely low chemical reactivity (hence the name inert gas).
• This is because all the noble gases have stable electronic configurations.
• This is the reason why noble gases do not form molecules easily and are mostly found as monoatomic gases.
• The general electronic configuration of the noble gases can be written as ‘ns2np6’.
• Therefore, the outermost valence shells of the noble gases can be considered as ‘full’.
• This is the reason behind the chemically inert nature of the group 18 elements.

• Boron is a chemical element with the symbol B and atomic number 5.
• Produced entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis.
• it is a low-abundance element in the Solar System and in the Earth's crust.
• It constitutes about 0.001 percent by the weight of Earth's crust.