Question

In a cell electrons move from:
A. Positive electrode to negative electrode.
B. Negative electrode to positive electrode.
C. Both A and B.
D. Electrons do not move and only negative charge moves from one place to another place.

Answer 1

Hint: Electrons are charge carriers for the flow of current. Additionally, the flow of current is taken as from positive electrode to negative electrode. So, the movement of the electrons inside the cell must be such that it is in agreement with this conventional rule.

Complete step by step answer:
The charged particles which by flowing in a definite direction set up an electric current are called current carriers. In metallic conductors, electrons are the charge carriers. The electric current is due to the drift of electrons from low to high potential regions.
In metals, the atoms are closely packed. The valance electrons of one atom are close to the neighbouring atoms and experience electrical forces due to them. So they do not remain attached to a particular atom, but can hop from one atom to another and are free to move throughout the lattice. These electrons are responsible for conduction in metals.
Now, when a cell is connected to a closed electric circuit, the electrons move from an area of low potential to an area of high potential. Additionally, this movement is in the opposite direction to the externally generated electric field. So, electrons tend to move from negative electrodes towards the positive electrodes. Thus negative charge flows from negative electrode to positive electrode. But on the contrary by convention the flow of charge is measured through the positive charges. This means that when an electron moves from the negative to positive electrode, an equal and opposite charge moves from positive to negative electrode.
Hence, the direction of movement of charge is taken as from positive electrode to negative electrode. Additionally, unlike charges attract each other and like charges repel each other, so the electrons move from negative to positive electrodes inside a cell.
Therefore, the correct option is B. i.e., In a cell electrons move from negative electrode to positive electrode

Note: When electrons move within a conductor they tend to collide with each other too. The average time between two consecutive and successive collisions of an electron is known as the relaxation time.