Question

(a) What is meant by the term orbital overlap? (b) Describe what a chemical bond is in terms of electron density between two atoms.

Short answer

(a) Orbital overlap refers to the interaction of electron clouds surrounding atomic nuclei when two atoms approach each other, which influences chemical bond formation and strength. (b) A chemical bond is formed when two atomic orbitals with their respective electron densities come close enough, leading to a region of enhanced electron density (covalent bond) that effectively "glues" the atoms together by balancing the repulsion between the positively charged nuclei. The greater the electron density in a chemical bond, the stronger the bond and the lower its potential energy.

Step-by-step solution

Define Orbital Overlap

Orbital overlap is the interaction of the electron cloud surrounding atomic nuclei when two atoms approach each other. It is a significant factor in the formation and strength of chemical bonds. In a valance atomic orbital (VAO), the electron density around the nucleus increases, which enhances orbital overlap. This interaction leads to the potential for bond formation through electron sharing.

Describe a Chemical Bond in Terms of Electron Density

Now, let's talk about chemical bonds in terms of electron density between the two interacting atoms. A chemical bond is formed when two atomic orbitals, each with its own electron density, come close enough together. This spatial overlap of atomic orbitals results in a region of enhanced electron density between the two atoms, known as a covalent bond. The increased electron density between the nuclei effectively "glues" the atoms together, as the mutual attraction between the nuclei and the shared electron pair helps balance the repulsion between the positively charged nuclei. In some cases, the electron clouds do not overlap directly but instead interact through the position of the electron density, as in the case of dative or coordinate bonds. The greater the electron density in a chemical bond, the stronger the bond, and the lower its potential energy.