Imagine you're sweating after a workout. This is your body’s way to cool down. Plants, in a way, 'sweat' too! This 'sweating' is called transpiration - it's the loss of water vapour from leaves and stems.

• Gas Exchange: Just like we need to breathe, plants also exchange gases. They take in CO₂ and give out O₂ through tiny pores on their leaves called stomata.
• Moisture Matters: For this exchange to work, the gas exchange surface must be wet. Why? Ever tried to whistle with a dry mouth? Not easy, right? Similarly, for effective gas exchange, plants need moisture!

• Evaporation: It's like water turning into 'mist'. It happens when individual water molecules leave liquid water and turn into gas. This gas is water vapour.
• Condensation: The opposite of evaporation. It's when water vapour molecules hug each other and turn back into liquid.
• Saturation Point: Imagine your sponge can't take any more water. This is its saturation point. Similarly, air reaches a saturation point with water vapour when the number of molecules evaporating equals those condensing.

Hotter Air: Can hold more water vapour. Think of it as a bigger backpack. Why? Higher temperature = More energy to break the 'handshakes' (hydrogen bonds) between water molecules.