Describe the methods by which an electric potential develops in primary cells and dry cells. Describe the methods by which an electric potential develops in generators and thermocouples.
Identify the scenarios below as to whether they would increase or decrease the resistance of an electric current through a body.

a. Increase the length of the conductor
b. Utilize a conductor with a larger cross-section
c. Cool the conductor to lower its temperature

If 0.8 Wh of electrical energy is lost as heat, how much heat energy (in Btu) is produced?
How many kilowatt-hours of energy would be used by a 40 W bulb that runs for 10 hours every day during the course of one year?

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false