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How do ionic compounds form from positive and negative ions?

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Two diagrams show the three-dimensional structure of a methane molecule: panel A uses a ball-and-stick model with a central carbon atom connected to four hydrogen atoms in a tetrahedral arrangement, while panel B illustrates the bond angle of 109.5 degrees and bond length of 1.09 angstroms between carbon and hydrogen atoms. — chemical compound Methane, in which four hydrogen atoms are bound to a single carbon atom, is an example of a basic chemical compound. The structures of chemical compounds are influenced by complex factors, such as bond angles and bond length.

Ionic compounds form through the process of ionic bonding, which relies on the permanent transfer of valence electrons from one atom to another.12

Typically, this occurs when a metal reacts with a nonmetal. The metallic atoms lose electrons from their outermost shell to become positively charged cations, while the nonmetallic atoms gain those electrons to become negatively charged anions. This transfer allows atoms to achieve a stable electron configuration, often resembling that of a noble gas, as described by the octet rule.134

Once these oppositely charged ions are in close proximity, they are held together by strong electrostatic forces of attraction. For the resulting chemical compound to be stable, the total number of electrons lost must equal the total number gained, ensuring the overall charge of the substance is zero. These ions then arrange themselves into rigid ionic lattice structures.12