42. Silicon is the main ingredient of both glass and semiconductor devices, yet the physical properties of glass are different from those of semiconductor devices. Explain.

The dissociation energy of a molecule is the energy required tobreak apart the molecule into its separate atoms. the dissociationenergy for a particular molecule is 5.48 x 10-18 j.suppose that this energy is provided by a single photon. determinethe (a) wavelength and (b) frequency of the photon

Aparticle's position is given by x = 3.00 - 9.00t + 3t2, in which x is in meters and t is in seconds. (a) what is its velocity at t = 1 s? (b) is it moving in the positive or negative direction of x just then? (c) what is its speed just then? (d) is the speed increasing or decreasing just then? (try answering the next two questions without further calculation.) (e) is there ever an instant when the velocity is zero? if so, give the time t; if not, answer "0". (f) is there a time after t = 3 s when the particle is moving in the negative direction of x? if so, give the time t; if not, answer "0".

Acold front traveling southeast collided with a warm front traveling northwest the following map shows the weather on monday the day the two fronts collided which of these describes the weather forecast for mississippi on tuesday and wednesday