Ionic Bonding: Videos & Practice Problems

Ionic bonding is a fundamental concept in chemistry that begins with understanding ions, which are atoms or molecules that carry a net electrical charge. This charge can be either positive or negative, resulting from the gain or loss of electrons. There are two primary types of ions: anions and cations.

Anions are negatively charged ions formed when an atom gains one or more electrons. The additional negatively charged electrons create an imbalance, resulting in a net negative charge. For example, a neutral hydrogen atom, which has one proton and one electron, becomes an anion when it gains an extra electron, leading to a total of two electrons and one proton. This results in a net negative charge, as the negative charge from the extra electron outweighs the positive charge from the proton.

On the other hand, cations are positively charged ions that occur when an atom loses one or more electrons. When a neutral hydrogen atom loses its single electron, it is left with only one proton and no electrons, resulting in a net positive charge. The loss of negatively charged electrons means that the positive charge from the protons is no longer balanced, thus creating a cation.

In summary, the key distinction between anions and cations lies in their charges: anions are negatively charged due to the gain of electrons, while cations are positively charged due to the loss of electrons. Understanding these concepts is crucial for exploring ionic bonding, where these charged ions interact to form compounds.

Ionic bonds are formed through electrical attractions between oppositely charged ions, specifically cations and anions. Unlike covalent bonds, which involve the sharing of electrons, ionic bonds are characterized by a complete transfer of electrons from one atom to another. This transfer allows both atoms to achieve full valence shells, which is crucial for their stability.

For example, in the formation of sodium chloride (NaCl), sodium (Na) has one electron in its outermost shell, while chlorine (Cl) is highly electronegative and has a strong tendency to attract electrons. The significant difference in electronegativity between sodium and chlorine results in chlorine effectively "stealing" the electron from sodium. As a result, sodium loses its single valence electron, leading to a full valence shell beneath it, while chlorine gains that electron, completing its own valence shell.

After this electron transfer, sodium becomes a positively charged ion (Na⁺), and chlorine becomes a negatively charged ion (Cl^-). The attraction between these oppositely charged ions forms the ionic bond. This interaction not only fills the valence shells of both atoms but also creates the ionic compound sodium chloride, which is commonly known as table salt.

In summary, ionic bonds are essential for the formation of stable compounds like NaCl, demonstrating how the transfer of electrons leads to the creation of charged ions that attract each other, resulting in a stable ionic structure.