Chemical bonding - am i right?

Question

I am doing some tutoring and want to check that I am correct when I say: Ionic bonding only happens in salts.That this is always between a metal ion and a non-metal ion, and that ionic structures are always 'giant' (and therefore crystals)? Does ionic bonding happen in simple molecules and what are examples of this if so? Thanks!

Answer 1

Ionic bonding also occurs in complexes, which consist of a (usually positive charged) central atom and several "ligands" which attach themselves as dipols or ions of the opposite charge.

The positive ion in a salt usually is a metal, but ammonia (NH4+) behaves almost like potassium, and ammonia derivates with one or several organic substituents for H form salts as well.

Crystals form when salts aggregate orderly. It is possible for salts to fail to form decently structured crystals, best known in the shape of sodium salts of fatty acids, aka soap.

Complexes can be rather simple, molecule-sized ions, e.g. (FeCl6)3- (which forms if you dissolve an iron salt in hydrochloric acid).

Certain organic molecules can form salts with themselves: amino acids at the iso-electric point are both the positive and the negative ion in the resulting insoluble material.

Answer 2

You are not completely right. The cation in salts is usually a metal ion, but not always (think of the ammonium ion).

In the solid, salts always form three-dimensional arrays (crystals) without distinct molecules. In solution, the cations and anions go their separate ways. So I would say that the solid structures are 3-D crystals, but they are not really "giant" the way that covalent network solids are.

At very high temperatures, salts form of what are called "ion pairs" in the vapour phase, but you don't meet this in ordinary chemistry.

Answer 3

while a chemical substitute happens (as in a chemical reaction) bonds are broken and then reformed in a distinctive configuration. staring on the form of bonds, this suggests that electrons would be shared or transfered between atoms while the recent bonds style.