The phenomenon that occurs when a liquid boils is called boiling. This process takes place when a liquid reaches its boiling point, where its vapor pressure equals the surrounding atmospheric pressure. At this point, bubbles of vapor form throughout the liquid and rise to the surface, causing the liquid to transition into a gaseous state. The boiling point varies depending on the substance and atmospheric pressure. For instance, at sea level, water boils at 100°C (212°F), but this point decreases at higher altitudes due to lower atmospheric pressure.