Difference between molecule and element

How did planetesmals form planets? a. they broke apart into smaller chunks. b. they collided and stuck together. c. they cooled and pulled ice together. d. they began to rotate.

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.

16. in a reaction that has reached equilibrium, a. the forward and reverse reactions are occurring at the same rate. b. the reactants and products are in equal concentrations. c. the forward reaction has gone further than the reverse reaction. d. there are equal numbers of atoms on both sides of the equation. e. a, b, and d are correct.