Why puttung lid on saucepan makes the water in it comes to boil come more quickly?

Putting a lid on a saucepan makes the water come to a boil more quickly because it traps heat and prevents heat loss to the surrounding air. Here's how it works:

* Conduction: The heat from the stove burner is transferred to the saucepan, and then to the water inside.

* Convection: As the water at the bottom of the saucepan heats up, it becomes less dense and rises, while cooler water sinks to take its place. This creates a circular flow, distributing heat more evenly throughout the water.

* Radiation: Some heat energy escapes from the water and the saucepan as infrared radiation.

When you put a lid on the saucepan, you significantly reduce the amount of heat lost through radiation and convection. This trapped heat is then used to raise the temperature of the water more quickly, leading to a faster boil.

Here's a simple analogy: Imagine you're trying to warm up a room using a heater. If you leave the windows and doors open, the heat will escape quickly, making it harder to reach a comfortable temperature. Similarly, leaving the saucepan uncovered allows heat to escape, slowing down the boiling process.

So, by putting a lid on your saucepan, you're essentially creating a "heat trap," allowing the water to absorb more of the heat energy and boil faster.