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H and 2nd Shell Electronegativity
Mrs. Cauthron expects you to know electronegativity values for hydrogen and the second-row elements by memory. With those, you can classify any bond as nonpolar covalent, polar covalent, or ionic without a chart.
Key Facts to Memorize
H
2.1 — close to carbon, which is why C–H bonds are nearly nonpolar.
Li
1.0
Be
1.5
B
2.0
C
2.5
N
3.0
O
3.5
F
4.0 — the highest of any element.
Bond classification
Difference < 0.5 nonpolar covalent; 0.5–1.7 polar covalent; > 1.7 mostly ionic.
Al says…
Memorize the pattern 'C 2.5, N 3.0, O 3.5, F 4.0' — it climbs by half a point each step. Hydrogen sits at 2.1, right below carbon.
Practice This Topic
External Tools
- Blooket review game
Coming soon — Mrs. Cauthron will post the game link here.
- Ptable electronegativity view
Check your recalled values against the real table.