International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

In the context of ionic compounds, what does the term 'giant structure' refer to?

1. A small number of atoms organized tightly

2. A crystalline arrangement of many ions

3. A single molecule held together by hydrogen bonds

4. A cluster of atoms with no real order

The correct answer is: A crystalline arrangement of many ions

The term 'giant structure' in the context of ionic compounds refers to a crystalline arrangement of many ions. This means that ionic compounds do not consist of just a few molecules; rather, they form a vast, three-dimensional lattice where positive and negative ions are held together by strong electrostatic forces of attraction. This structure is responsible for the characteristic properties of ionic compounds, such as high melting and boiling points, as a considerable amount of energy is required to break the ionic bonds within the lattice. In a giant ionic structure, ions are arranged in a highly ordered pattern, maximizing the attraction between oppositely charged ions while minimizing repulsion between ions of the same charge. This arrangement contributes to the stability and integrity of the compound. The other options do not accurately depict the nature of ionic compounds. A small number of atoms organized tightly does not reflect the extensive arrangement typical of giant ionic structures. A single molecule held together by hydrogen bonds suggests a discrete molecular structure, which is not applicable to ionic compounds that exist as extensive lattices. A cluster of atoms with no real order describes a more amorphous structure, which contrasts with the organized, repeating units found in ionic lattices.