a) H₂O
b) NaCl
c) CO₂
d) O₂
For Explanation Click Here:
Ionic bonds are formed when electrons are transferred from one atom to another. In NaCl, sodium (Na) donates an electron to chlorine (Cl), resulting in a positively charged sodium ion (Na⁺) and a negatively charged chloride ion (Cl⁻), forming an ionic bond. In contrast, H₂O, CO₂, and O₂ all involve covalent bonds where electrons are shared between atoms.