Question

Considering that electricity is the flow of electrons from one place to another, propose an explanation for why metals are generally good conductors of electricity, whereas covalently bonded compounds are not.

Short answer

Metals, having a 'sea of electrons', allow the free electrons to move, facilitating the flow of electric current, hence, they are good conductors of electricity. Conversely, in covalently bonded compounds, there are no free electrons to move, limiting the flow of electric current, making them poor conductors of electricity.

Step-by-step solution

Understand Metallic and Covalent Structure

Metals have a unique 'sea of electrons' structure where the electrons from the outer-most shell of the atoms are free to move. In contrast, in covalently bonded compounds, electrons are shared between atoms, and each electron is tied to a particular atom, hence, they lack free electrons.

Relate Electronic Structure to Electrical Conductivity

In a metal, the free electrons can easily move in response to an electric field (like a voltage difference), and this movement of electrons constitutes an electric current. Hence, metals are generally good conductors of electricity.

Explain Why Covalently Bonded Compounds are Poor Conductors

In covalently bonded compounds, the lack of free electrons implies limited or no ability for electron motion when an electric field is applied. Therefore, covalently bonded compounds are generally poor conductors of electricity.