Which statement best describes semi-conductors? Lack free electrons that can move to other atoms Electrons within their atoms are strongly held by the nuclei Most electrons within their atoms are paired Electricity can flow through it under special conditions

Which of the following quantities are units of momentum? (there could be more than one correct choice.) a)n m b) kg s/m c) kg m/'s d)n-s 12 points] e) kg m2/s2

An ionic compound can conduct electricity when a it is dissolved in water b its crystals are ground into powder c it is in solid form d it is heated to just below its melting point

Ablock having mass m slides down an inclined plane. the force of friction between the block and the inclined plane is f, the block's weight is m g, and the normal force is n. (a) draw a free – body force diagram showing the forces acting on the block. (b) write down all relevant newton’s equations for a given situation.