9701 · 3.1
Electronegativity and bonding — FAQ
Frequently asked questions for 9701 Electronegativity and bonding. Direct answers first, then deeper explanation — then practise with marking.
Are the specific Pauling electronegativity values provided in the exam?
Usually, you are expected to know the general trends (increasing across a period, decreasing down a group). If a question requires a specific calculation of ΔEN, the values will almost always be provided in a data table.
Is there a strict numerical cut-off between polar covalent and ionic bonds?
No, the value of ΔEN ≈ 1.7 is just a useful guideline. Bonding is a continuum. Some compounds with a ΔEN below 1.7 show ionic characteristics, while some above it have covalent character. The key concept is that ionic character increases as ΔEN increases.
Why don't noble gases like Neon or Argon have electronegativity values?
Electronegativity is defined for an atom attracting electrons within a covalent bond. Since noble gases have a full valence shell, they are very stable and do not readily form covalent bonds. Therefore, the concept of electronegativity is not typically applied to them.