hot air.
^^Close. It is actually steam or the gaseous form of H2O (water). As the water is heated it changes from a liquid to a gas. Since the heat is coming from the bottom (in a pot) and the top of the water is cooler, the gas forms bubbles.
When water boils, the bubbles are made of water vapor. Water is changing from the liquid phase to the gas phase, but it doesn't change all at once, so you get bubbles of gas inside the liquid. The phase change will happen first at the location where heating is taking place, so if you have a pot on a stove, the bubbles will form at the bottom of the pot, and then rise to the top.
It is an event called vaporization.
There's different reasons why air bubbles 'break'. It also depends on what type of air bubbles? The ones that 'break' when you boil water break because boiling water weakens the intermolecular forces of water that help it have properties such as the cohesive properties of water which make water have high superficiality. What this means is that water molecules can attach to other water molecules through hydrogen bonding with other oxygens of other water molecules, they can also attach to each other by dipole-to-dipole attraction due to the polarity of water. All this properties of water make it be able to form bubbles or in other words to form a layer of water around gas particles that are inside of that layer and hold it in a round form. As temperature increases(boiling the water) these forces become weaker and the water is not able to hold the gas inside in a bubble which causes the bubble to break. Also, the fact that gaseous water is much lighter than liquid water makes the gas inside the bubble to tend to push up.
Misty fogs form when water boils because the hot water vapor comes into contact with cooler air, causing it to condense into tiny water droplets that we see as mist. This process occurs when the warm air, saturated with water vapor, meets a cooler surface, leading to condensation and the formation of mist.
Dissolved air bubbles out of the water, as the boiling point of water is reached, water vapour starts to form inside the liquid in the form of bubbles
When water boils, bubbles form due to the release of water vapor from the liquid. These bubbles contain water vapor, not air. The water itself does not disappear; it is transformed into water vapor, which you see as bubbles.
Water vapor (steam) is inside the bubbles that form inside boiling water. The bubbles that form prior to boiling are mostly dissolved gases escaping from the water.
A bubble can freeze when the water film inside the bubble cools down rapidly, causing the water molecules to slow down and form into a solid. This process is similar to how water freezes into ice, but in the case of a bubble, the thin film of water solidifies into a delicate ice structure.
Water vapour
Water vapour
Water vapour
Below the surface
When water boils, the bubbles are made of water vapor. Water is changing from the liquid phase to the gas phase, but it doesn't change all at once, so you get bubbles of gas inside the liquid. The phase change will happen first at the location where heating is taking place, so if you have a pot on a stove, the bubbles will form at the bottom of the pot, and then rise to the top.
It is an event called vaporization.
It starts from 100 celcius in 1atm and can be risen further. At lower pressures eg on tops of mountains, it can be lower. Water boils when the pressure of water vapour exceeds the external atmospheric pressure. Below that, any bubble of water vapour which might start to form is immediately compressed back to liquid.
When water is heated, energy is being added to it, this causes it to change form a liquid to a gas
There's different reasons why air bubbles 'break'. It also depends on what type of air bubbles? The ones that 'break' when you boil water break because boiling water weakens the intermolecular forces of water that help it have properties such as the cohesive properties of water which make water have high superficiality. What this means is that water molecules can attach to other water molecules through hydrogen bonding with other oxygens of other water molecules, they can also attach to each other by dipole-to-dipole attraction due to the polarity of water. All this properties of water make it be able to form bubbles or in other words to form a layer of water around gas particles that are inside of that layer and hold it in a round form. As temperature increases(boiling the water) these forces become weaker and the water is not able to hold the gas inside in a bubble which causes the bubble to break. Also, the fact that gaseous water is much lighter than liquid water makes the gas inside the bubble to tend to push up.