How does an ionic bond differ from a covalent bond?

Ionic bonds transfer electrons and covalent bonds share electrons.

Explanation:

Ionic bonds tend to transfer electrons completely. Take NaCl for example.

Cl has 7 valence electrons.

Na has 1 valence electron.

To stabilize themselves, either with a full 8 shells or full outer shell, Cl wants 1 electron and Na wants to lose 1 electron. So when NaCl forms, Na donates its electron to Cl.

In a covalent bond, the electrons are shared. Water can be used as an example. The electrons in water usually are around the oxygen, but sometimes it is around the hydrogens.

the dissolution of polymer can be thermodynamically described in 2 steps.