1a Are the following chemical changes or physical changes.1. cobalt chloride paper going blue2. colored posters fading3. copper bar expanding4. copper going green5. natural gas burning1b. Cora said litmus paper turning from red to blue was a chemical change because blue color meant it must be a new substance. Dan said it must be physical change because it is so easy to turn litmus paper back to red again.Do you agree with Cora or Dan? Explain answer.well number 1b is the most confusing one, can u please explain it to me.
driving a motorcycle whose brakes dont work
The motorcycle with no brakes is definitely deadly. The car with the nut could be too. I would have to say the motorcylce, though.
1-? is the paper getting put in another chemical? If not, and the paper still has the same chemical makeup, then it is a physical change. 2-? This one I think it is physical because the dyes might be evaporating(?). It also could be chemical. not entirely sure. 3-Physical (the copper is still copper afterwords) - I'm positive 4-Chemical - it is reacting to form a new copper compound - I'm positive 5-This is a chemical change - the Natural gas reacts with O2 and forms CO2 and H20 (vapor) - I'm positive 1b - this is definitely a chemical change. Because the color is different from acid to base, a chemical property must be affecting the outcome of the color. Litmus paper requires a chemical reaction to work. I don't think that when the paper is turned colors from the acid, that adding a base will change the color back.
being with the crazy nutt case.
