i dont fully understand the question, do you mean the black almost burnt looking substance? which would be soot made from carbon which is the same thing in chimneys
A reaction of oxydation with the oxygen from air.
Aluminum oxide is Al2O3 and when heated it is still Al2O3, so heating aluminum oxide does nothing to it.
Heated from the bottom, the warmer substance will slowly rise to the top while the cooler substance at the top falls to the bottom to be heated again. Look at a lava lamp. That is all about convection currents.
When limestone is heated, it undergoes a chemical reaction called thermal decomposition, where it breaks down into calcium oxide (quicklime) and carbon dioxide gas. This is a chemical change because the chemical composition of the substance is altered during the process.
Bubbles forming on heated water are usually due to the process of water vaporization rather than a chemical reaction. When water is heated, the molecules gain energy and move faster, eventually reaching a point where they break free from the liquid surface and form bubbles of water vapor. This phase change is a physical process, not a chemical reaction.
A reaction of oxydation with the oxygen from air.
It would be chemical.
Aluminum oxide is Al2O3 and when heated it is still Al2O3, so heating aluminum oxide does nothing to it.
chemical
Adding water to heated copper sulfate crystals is a chemical change. When water is added to heated copper sulfate crystals, the copper sulfate undergoes a chemical reaction where it dissolves in the water to form a solution. This is a chemical change because the chemical composition of the copper sulfate is altered during the process.
That would be a chemical property demonstrated by a chemical change.
chemical equation of heated iron and sulfur is as follows. FeS can be obtained by the heating of iron and sulfur:Fe + S → FeS.
Vapor, its chemical elements do not change.
yes
Heated from the bottom, the warmer substance will slowly rise to the top while the cooler substance at the top falls to the bottom to be heated again. Look at a lava lamp. That is all about convection currents.
2KClO3 ----> 2KCl + 3O2
This is a thermal decomposition.