How do the structures of ionic and covalent compounds differ?

Ionic compounds are formed from positive and negative ions, while covalent compounds are formed by sharing electrons between atoms.

Ionic compounds are formed when a metal reacts with a non-metal. They are composed of positive and negative ions, which are held together by strong electrostatic forces of attraction. This is known as ionic bonding. The metal atoms lose electrons to become positively charged ions, while the non-metal atoms gain these electrons to become negatively charged ions. The resulting compound is neutral because the total positive charge of the metal ions equals the total negative charge of the non-metal ions. Ionic compounds often form crystalline structures and have high melting and boiling points due to the strong forces of attraction between the ions.

On the other hand, covalent compounds are formed when two non-metals react together. Instead of transferring electrons as in ionic bonding, the atoms share electrons. This is known as covalent bonding. Each atom contributes at least one electron to the shared pair, which is often referred to as a bonding pair of electrons. The shared electrons are attracted to the nuclei of both atoms, which holds the atoms together in a covalent bond. Covalent compounds can exist as simple molecules or as giant covalent structures. Simple molecular substances have low melting and boiling points and do not conduct electricity. Giant covalent structures, however, have high melting and boiling points as a lot of energy is needed to break the many strong covalent bonds.

In summary, the key difference between ionic and covalent compounds lies in the way the atoms are bonded together. In ionic compounds, electrons are transferred and ions are formed, while in covalent compounds, electrons are shared between atoms.