Direct comparison
For “is c more or less electronegative than n”, carbon (C) is less electronegative than nitrogen (N). Nitrogen attracts shared bonding electrons more strongly than carbon.
Electronegativity meaning in general chemistry
Electronegativity is a relative measure of how strongly an atom attracts electron density in a chemical bond. It is not a directly measured thermodynamic quantity, but a useful scale that correlates with bond polarity, dipole moments, and trends across the periodic table.
Reference scale and representative values
A common reference is the Pauling electronegativity scale. Representative values are:
| Element | Symbol | Pauling electronegativity (approx.) | Relative order |
|---|---|---|---|
| Carbon | C | 2.55 | Lower |
| Nitrogen | N | 3.04 | Higher |
Periodic-table explanation
Carbon and nitrogen lie in the same period (Period 2). Across a period, electronegativity generally increases from left to right. The primary driver is increasing effective nuclear charge \(Z_\text{eff}\) felt by valence electrons while shielding changes modestly, so the atom exerts a stronger attraction on shared electron density in a bond.
- Across a period: increasing \(Z_\text{eff}\), smaller atomic radius, stronger attraction for bonding electrons.
- Down a group: increased principal quantum number \(n\), larger radius, greater shielding, weaker attraction for bonding electrons.
Visualization: C vs N on Period 2 and the direction of increasing electronegativity
Consequences for bond polarity and Lewis representations
A difference in electronegativity \(\Delta \chi = \chi(\mathrm{N}) - \chi(\mathrm{C})\) supports a polar covalent C–N bond. Using representative Pauling values gives:
\[ \Delta \chi \approx 3.04 - 2.55 = 0.49. \]
A moderate \(\Delta \chi\) typically corresponds to a polar covalent bond rather than an ionic bond. In Lewis terms, electron density is drawn toward nitrogen, which can stabilize negative formal charge on N in some resonance forms and can increase the basicity/acid-base behavior relevance of nitrogen lone pairs in amines, amides, and related functional groups.
Fine points that preserve the ordering
- Hybridization effects: carbon electronegativity can increase from sp3 to sp2 to sp due to increasing s-character, yet nitrogen remains higher in typical bonding contexts.
- Scale dependence: numerical values change slightly between electronegativity scales, while the ordering \( \chi(\mathrm{N}) > \chi(\mathrm{C}) \) remains consistent.
- Bond environment: substituents and resonance alter charge distribution, but the intrinsic atomic trend continues to pull electron density toward N in a C–N bond.