Water (H2O) can indeed decompose into hydrogen (H2) and oxygen (O2) when exposed to electricity. This process is known as electrolysis. When an electric current is passed through water, it causes the water molecules to undergo a chemical reaction.
During electrolysis, the water molecule is split into its constituent elements: hydrogen and oxygen. This occurs at the electrodes, which are typically made of materials like platinum or graphite. The positive electrode, known as the anode, attracts negatively charged ions (anions) and undergoes oxidation. At the anode, water molecules lose electrons and release oxygen gas (O2):
2H2O(l) → O2(g) + 4H+(aq) + 4e-
The negative electrode, called the cathode, attracts positively charged ions (cations) and undergoes reduction. At the cathode, water molecules gain electrons and produce hydrogen gas (H2):
4H2O(l) + 4e- → 2H2(g) + 4OH-(aq)
Overall, the balanced equation for the electrolysis of water is:
2H2O(l) → 2H2(g) + O2(g)
It's important to note that electrolysis requires an external source of electrical energy to drive the reaction. Without electricity, water will not spontaneously decompose into hydrogen and oxygen gas.