Question
Question: Name the particles which are responsible for the flow of current in a metal A. electrons B. prot...
Name the particles which are responsible for the flow of current in a metal
A. electrons
B. protons
C. neutrons
D. free electrons
Solution
Electric current is the rate of flow of electric charges. These electric charges as the name suggest are charged particles whose motion produces current. The charge carriers can vary and depend on the material. The SI unit of current is given as ampere A.
Complete step-by-step answer:
We know that materials are classified into conductors and insulators depending on their ability to allow the flow of charges.
Clearly, conductors are materials that allow the flow of charges through them. And Insulators are materials that resist the flow of charges through them. Clearly, the charge carrier must be free to move.
A few examples of conductors include metals, electrolytes, gases and semiconductor.
Here we are talking of metals. We know that metals are made up of atoms. We know that the atom consists of neutrons, electrons and protons. Clearly, neutrons are not charged, thus C is not the answer.
We know that an atom is neutral, as they contain an equal number of electrons and protons. The protons and electrons are held together by some attractive force. When an electrical potential is applied to a metal, the attractive force gets disturbed. Thus the electrons become free to move. Clearly the electrons are negatively charged and can carry the flow of electricity.
But the charge carrier must be free to move; hence option A and B is not correct.
Hence in metals the flow of electrons causes electricity.
Hence the answer is D. free electrons
So, the correct answer is “Option D”.
Note: The flow of ions causes electricity in electrolytes and gases. While the flow of holes causes electricity in the semiconductors. The flow of free electrons causes electricity in metals. Then we can say that the rate of flow of free electrons creates current in metals.