A Level Chemistry OCR Practice Exam

What is a metallic bond?

1. The attraction between metal ions and non-metal ions

2. The electrostatic attraction between positive metal ions and delocalised electrons

3. The bond formed between two metal atoms

4. The covalent bond that occurs in metal oxides

The correct answer is: The electrostatic attraction between positive metal ions and delocalised electrons

A metallic bond is characterized as the electrostatic attraction between positive metal ions and delocalised electrons. In metallic structures, metal atoms release some of their electrons, which are then free to move throughout the metal lattice. These delocalised electrons create a 'sea of electrons' that are not bound to any specific atom, allowing them to move freely. This electron mobility contributes to many properties of metals, such as conductivity, malleability, and ductility. The presence of this 'sea of electrons' allows for the attractive forces between the positively charged metal ions (cations) and the delocalised electrons to hold the structure together firmly, giving metals their characteristic strength and stability. The nature of these bonds is essential in understanding how metals behave in chemical and physical processes. In contrast, the other options describe different types of bonding or interactions that do not accurately capture the essence of metallic bonding. For example, the first option refers to ionic bonds, which involve the attraction between metal and non-metal ions but do not involve delocalised electrons. Similarly, the bond between two metal atoms would suggest a covalent or coordinated bond rather than a metallic bond. Finally, option D incorrectly characterizes the interaction in metal oxides as covalent, which