## Explanation

### Convection as the Main Mode

When water is boiled, the primary mode of heat transfer occurring in the water itself is **convection**. Convection involves the movement of fluid molecules, which transfer heat through both advection and diffusion. In boiling water, hotter water at the bottom rises to the top, while cooler water descends to the bottom. This creates a circulation pattern that evenly spreads heat throughout the entire volume of water.

Where:

- $Q$ is the heat energy
- $m$ is the mass of the water
- $c$ is the specific heat capacity of the water
- $\Delta T$ is the change in temperature

### Conduction in Boiling Water

**Conduction** also plays a role, but it is secondary compared to convection. This form of heat transfer happens primarily at the boundary between the hot surface of the pot and the water. The heat from the burner is first transferred to the pot, and then from the pot to the water through conduction.

Where:

- $q$ is the heat flux
- $k$ is the thermal conductivity of the pot material
- $A$ is the area through which heat is conducted
- $\frac{dT}{dx}$ is the temperature gradient

### Role of Radiation

While **radiation** is the least significant of the three mechanisms in the context of boiling water, it is not completely absent. Radiative heat transfer occurs when electromagnetic waves are emitted by the heat source (e.g., the burner) and absorbed by the pot and water. However, the contribution of radiation to the overall boiling process is minimal compared to the dominant mechanism of convection and secondary conduction.

Where:

- $\epsilon$ is the emissivity of the pot's surface
- $\sigma$ is the Stefan-Boltzmann constant
- $A$ is the area of the pot
- $T$ is the temperature of the pot
- $T_{ambient}$ is the ambient temperature

In summary, boiling water primarily involves **convection** as the main mode of heat transfer, with **conduction** playing a secondary role, and **radiation** having a minimal effect.