The reaction between water and sodium is a classic example of a single-displacement reaction. In this reaction, sodium, a highly reactive metal, displaces hydrogen from water to form sodium hydroxide (NaOH) and hydrogen gas (H2). The overall chemical equation for this reaction is:

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

Here's a more detailed explanation of what happens during this reaction:

1. Sodium atoms (Na) in the metal come in contact with water molecules (H2O).

2. Sodium atoms being highly electronegative, readily donate their outermost electron to the electronegative oxygen atom of the water molecule.

3. As a result, the sodium atom transforms into a positively charged sodium ion (Na+), and the water molecule gains an extra electron, becoming hydroxide ion (OH-).

4. These ions are then solvated by the remaining water molecules, forming sodium hydroxide (NaOH), a strong base that is soluble in water.

5. Simultaneously, the hydrogen atoms in the water molecule, now lacking an electron, combine to form hydrogen gas (H2).

6. Hydrogen gas, being less dense than water, rises to the surface and can be observed as bubbles or collected in an appropriate container.

The reaction between water and sodium is highly exothermic, meaning that it releases a significant amount of heat. This heat can cause the water to boil and produce a vigorous reaction. It is important to note that this reaction should be conducted with caution and proper safety measures, such as wearing protective clothing and eye goggles, due to the flammable nature of hydrogen gas and the causticity of sodium hydroxide.