Is there a bond between sodium chloride molecules?

Answer 1

This is a very vexed question. In modern usage, there isn't any such thing as a sodium chloride molecule. We reserve the term for covalent substances. (I was taught the old way, but now we try to think in terms of the actual particulate structure of substances.) Sodium chloride is a three dimensional assembly of positive sodium ions and negative chloride ions. The force of electrostatic attraction holds them all together. This is the bonding in an ionic substance.

http://www.bbc.co.uk/schools/gcsebitesize/science/add_gateway_pre_2011/periodictable/ionicbondingrev2.shtml

In a covalent substance such as sulfur, the question has more meaning. Sulfur atoms share electrons and form a sulfur molecule. The shared pairs of electrons are covalent bonds, which produce S8 molecules (don't forget the 8 is a subscript). That leads to the question 'what holds these molecules together in a lump of sulfur?' We then need to discuss intermolecular forces. In sulfur these are van der Waals' forces.

Answer 2

No, there is no covalent bond between sodium chloride molecules. Sodium chloride forms an ionic bond, where the sodium atom donates an electron to the chlorine atom, creating positively charged sodium ions and negatively charged chloride ions that are attracted to each other through electrostatic forces.