9) how do you know a chemical change has occurred? a. new bonds have formed or bonds have broken. b. the matter has had a change in state. c. the temperature has changed. d. all of the above e. only a and c are indicators of a chemical change.

What is the volume occupied by 10.0 dm3 of gas at standard pressure after it has been compressedat constant temputure to 500.0 kpa?

Fossil fuels are organic compounds that are made from

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.