Question

When the current is allowed to pass from a potato, a greenish-blue spot appears on it. The spot appears because of which chemical? Answer me fastt...... experts

Answer 1

The potato itself has a mixture of starches and salts and some water. A salt, like table salt, in water releases ions. Ions are atoms that have an electrical charge. When a metal (copper) reacts with a positively charged ion, like the positively charged sodium ion in the salt in a potato - the metal gets a bit of a positive charge. Positive electrical charges and negative electrical charges attract each other. The positive charge in the metal will attract negatively charged electrons. Electrons are the carriers for electricity. And when these electrons leave the positive terminal of battery, bluish green colour is appears at the potato. This signifies potato can conduct electricity and the bluish green colour is the positive terminal of the battery.  The bluish green spot is because of formation of copper complex.