When 100 j are put into a device that puts out 40 j, the efficiency of the device is a. 40%. b. 50%. c. 60%. d. 140%.

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

Based on the concept of the wave-like nature of light, huygens' theory of light postulates that the more light was "bent" by a substance the slower it would move while traversing across that substance. a) deflection b) interference c) refraction d) resonance

What structural formula represents 4 electrons shared between two atoms?