no it is not a chemical change but physical change as it can be turned back to gas by some physical or chemical process.
change a when the gas goes from liquid to gas is a physical change. Change b when the gas burns is a chemical change
nothing
physical change
what you freeze is the same that comes in to a liquid and it does it over and over
I doubt it. Color-change is an indication of a chemical reaction. Gold, however, is generally non-reactive (although highly conductive), which is why it doesn't tarnish or rust. Since I cannot think of another chemical gold reacts easily with, I'm giving a tentative "no" to your question.
change a when the gas goes from liquid to gas is a physical change. Change b when the gas burns is a chemical change
nothing
Melting, the phase change from a solid to a liquid, is considered a physical change rather than a chemical change because when the phase change takes place, the substance that was melted does not change its chemical composition, and the process could be reversed to get the original condition of the substance by freezing (liquid-solid).
chemical change
the physical comes from the chemical explosion
physical change
Olive DRAB (Dust Recognizable as Blister agent) is a chemical powder that changes color when it comes in contact with liquid nerve or blister agents. It is used as a protective measure to detect the presence of these harmful substances. The color change serves as an indicator and can help identify the presence of chemical warfare agents.
what you freeze is the same that comes in to a liquid and it does it over and over
That's depending of the design, outer measures, kind of glass, but merely on the thickness of (the wall and bottom of) the glass cylinder.
I doubt it. Color-change is an indication of a chemical reaction. Gold, however, is generally non-reactive (although highly conductive), which is why it doesn't tarnish or rust. Since I cannot think of another chemical gold reacts easily with, I'm giving a tentative "no" to your question.
there are two types of change. the first one is the physical change. the form or appearance of the substance is change but the chemical properties of the substance is not changed. example, water evaporates into the air, that is a physical change because from liquid, water changes into gas but it then comes back to water as rain. the other one is chemical change wherein the chemical properties of the substance is changed. example is burning of wood. wood is burned and turned into charcoal. the chemical properties of wood is different from the chemical properties of charcoal and charcoal is another substance.
It's a chemical change because a new substance comes out of tarnishing.