# Chemistry 101 Question

1. Sep 3, 2008

### Chemistry101

1. Although we have to write sodium chloride as NaCl, we realize that NaCl is an ionic compound and contains no molecule. Explain.

I kind of came up with an idea that sodium is a positive charge and chlorine is a negative charge. Is this the reason why they have no molecules? Is that what the question is asking?

Thanks.

2. Sep 3, 2008

### Ygggdrasil

The term molecule implies a collection of atoms that are covalently bonded together into a discrete unit with a defined composition (e.g. all water molecules have exactly 2 hydrogen atoms and exactly one oxygen atom). In contrast, ionic solids such as NaCl exist as a crystal lattice (see diagram on wikipedia http://en.wikipedia.org/wiki/Sodium_chloride). In the crystal, each chloride is surrounded by sodium ions and each sodium ion is surrounded by chloride ions. Since these crystals can vary in size, the crystals can have varying numbers of sodium and chloride ions; however, the ratio of sodium and chloride ions in the crystal is fixed and is always 1:1 (this is necessary for the crystal to be neutrally charged overall).

3. Sep 3, 2008

### Chemistry101

I asked for an easier interpretation not a copy and paste answer.