Video Transcript
Which of the following is the best description of electrical conduction in a solid metal? (A) Positive ions flow through a lattice of negative ions. (B) Negative ions flow through a lattice of positive ions. (C) Positively charged elementary particles flow through a lattice of negative ions. (D) Negatively charged elementary particles flow through a lattice of positive ions. Or (E) positively charged elementary particles flow through a lattice of positive ions.
In this question, we want to determine which choice best describes electrical conduction in a solid metal.
Metals form as the valence electrons of metal atoms group and make one sea of delocalized electrons. The metal atoms effectively turn into cations, as their valence electrons group and essentially decouple from the neutrally charged metal atoms. Scientists describe these electrons as delocalized since they are not close to one metal cation but rather are dispersed throughout the lattice of cations and freely move among them.
A metallic bond is a strong electrostatic force of attraction between these positively charged cations and the negatively charged delocalized valence electrons. Metallic bonds give metals distinctive properties, such as high melting points. Metals are also good conductors of heat and electricity because the delocalized electrons are highly mobile and can move freely. Electrons can move from the negative terminal of an electric circuit to its positive terminal.
Metals usually have a higher electrical conductivity value if they have more valence electrons. Here is an example of this relationship. Sodium has a low electrical conductivity value because it has one valence electron. Magnesium and aluminum have higher electrical conductivity values because they have two and three valence electrons, respectively.
Since we have seen that electrical conduction in metals is the flow of negatively charged electrons through a lattice of cations, we can deduce that answer option (D) is correct. Electrons are elementary particles because they are not a composite of smaller particles.
So which is the best description of electrical conduction in a solid metal? (D) Negatively charged elementary particles flow through a lattice of positive ions.
