H and 2nd Shell Electronegativity: Sample Problems

Try each one on paper first. Only then reveal the solution — reading a worked answer you never attempted teaches you almost nothing.

1. 1. Classify the O–H bond in water.

   Show solution

2. 2. Is LiF ionic or covalent?

   Show solution

3. 3. Rank C–F, C–O, and C–N by increasing bond polarity.

   Show solution

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.