Final answer:
An ionic bond forms when valence electrons are transferred from one atom to another, creating ions (cations and anions) that are electrostatically attracted to each other, as seen in the formation of calcium chloride (CaCl2) from calcium and chlorine atoms.
Step-by-step explanation:
Understanding Ionic Bonds through Electron Transfer
When valence electrons are transferred from one atom to another, an ionic bond is formed. This typically occurs between atoms with significantly different electronegativities. For example, calcium (Ca), which has two valence electrons, can transfer these electrons to two chlorine (Cl) atoms, each needing one electron to complete its octet. As a result, the Ca atom loses electrons to become a positively charged cation (Ca2+), while each Cl atom gains an electron to become a negatively charged anion (Cl-). The resulting Ca2+ and Cl- ions are attracted to each other due to electrostatic forces, forming an ionic compound such as calcium chloride (CaCl2). This interaction exemplifies how ionic compounds, or salts, are held together by electrostatic attraction rather than specific geometric arrangements as seen in covalent compounds.