An ionic bond is the electrostatic attraction between oppositely charged cations and anions held together in a crystal lattice. It typically forms between a metal, which loses electrons to become a cation, and a non-metal, which gains them to become an anion. These strong attractions give ionic compounds high melting points, in contrast to the weaker forces between molecules.

离子键是带相反电荷的阳离子与阴离子在晶格中相互结合的静电吸引。它通常形成于失去电子成为阳离子的金属与得到电子成为阴离子的非金属之间。这些强烈的吸引使离子化合物具有高熔点;与之相对的是分子之间较弱的作用力。