How do sodium and chloride ions hold together in a solid crystal?

Question

Nolan Allen · Accepted Answer

The ions are held together by strong electrostatic forces.

Ions with unlike charges attract each other.

The positive Na⁺ ions attract the negative Cl⁻ions.

But they repel other Na⁺ ions, because ions with like charges repel each other.

As a result, each Na⁺ will try to surround itself with as many Cl⁻ ions as possible. It can fit six Cl⁻ ions around itself.

Also, each Cl⁻ will try to surround itself with as many Na⁺ ions as possible. Again, it can fit six Na⁺ ions around itself.

The ions arrange themselves in the shape of a cube.

This pattern is repeated throughout the crystal.

The pattern is not open, as in the above diagram, because the oppositely-charged ions "want" to get as close to each other as possible.

They are, in effect, touching each other, as in the picture below.

Note: There is an Na⁺ ion "hidden" in the centre of the cube.

Ryan Andrews · Answer

undefined Sodium and chloride ions hold together in a solid crystal through ionic bonding. In a sodium chloride crystal lattice, each sodium ion is surrounded by six chloride ions, and each chloride ion is surrounded by six sodium ions. The electrostatic attraction between the positively charged sodium ions and the negatively charged chloride ions holds the crystal together in a stable structure. This arrangement results in a repeating pattern of alternating positive and negative ions throughout the crystal lattice.