A piece of copper wire is placed in a beaker containing a solution of silver nitrate. Which statement is an observation? A.
Mercury is a liquid at room temperature.
B.
Ethanol changes from a liquid to a vapor at 78.4°C.
C.
Hydrogen bonding is stronger in water than in acetone.
D.
Lead has a higher density than iron at room temperature.

List four observations that indicate that a chemical reaction may be taking place

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced.be sure your answer has the correct number of significant digits.

Heat is the total potential energy of a substance that can be transferred. true false