(a) in tin at room temperature, the mobility of mobile electrons is about 1.5 ✕ 10-3 (m/s)/(v/m), and there are about 3.7 ✕ 1028 mobile electrons per m3. calculate the conductivity σ. in actual practice, it is usually easier to measure the conductivity σ and deduce the mobility u from this measurement.

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods

according to jean piaget, in what stage of cognitive development are children able to understand conservation task?

b. preoperational

just took it