Identify the substance that is widely used as electrodes in batteries.
Graphite
Electrodes in batteries:
Explanation for correct option:
(A) Graphite being an excellent conductor is used in electrodes in batteries for electrolysis. When it comes to the structure of graphite, there are a high number of delocalized electrons (free electrons) present which enables the electricity to pass through graphite easily. Another reason for utilizing graphite in electrodes is its capability to resist high heat as it has high melting point. Also graphite is inexpensive and easily available.
Explanation for incorrect options:
All the above cited reasons qualify graphite for being used in an electrode in batteries. Coke, lampblack and wood charcoal are bad conductors of heat and electricity, hence can't be used in electrodes.
Thus, option (A) is correct. Graphite is the substance that is widely used as electrodes in batteries.