What happens when a rock is physically or chemically changed?

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?

What is created when solids,liquids,an gases mix with one another

J. j. thomson’s experiment disproved the theory that an atom