Chemistry · Chapter 7

Ionic Lattice Builder

An ionic solid is a repeating grid of ions. Pick the two ions, then pull the grid apart and watch the energy fall. Charge and distance are the only two dials that matter.

The lattice NaCl

Ion lattice

Ions of opposite charge alternate in every row and column.

Energy against distance 1 / r

Lattice energy falls as 1 over r

The curve is the same ΔHlattice ∝ Q1Q2/r rule. Double the distance and you halve the energy.

Build your solid

Live numbers

Charge product
1
r₀ touching
283 pm
Spacing now
283 pm
Model energy
769 kJ/mol
Model at r₀769 kJ/mol
Measured value769 kJ/mol

The model and the measured value agree to 0 percent.

What you are seeing
Table salt, NaCl
Sodium gives up one electron and chlorine takes it.