If a substance has an excess number of electrons on its surface, what type of charge does it have?

Which is not a characteristic of a heat pump? a. it is used in air conditioners. b. it uses a refrigerant. c. it requires no work. d. it reverses the normal flow of thermal energy.

Ms.hidalgo opens the door to her classroom. her classroom is 60 degrees and the air outside is 80. predict what will happen using your knowledge of how heat flows.

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above