What are the two most reactive groups of elements in the periodic table?

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?

The mini-refrigerator fire was most likely caused by what type of wiring?

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is