When a piece of polythene is rubbed with with a dry woollen cloth, electrons move from the cloth to the polythene. Which material becomes.

Consider the two electron arrangements for neutral atoms a and b. are atoms a and b the same element? a - 1s2, 2s2, 2p6, 3s1 b - 1s2, 2s2, 2p6, 5s1

Often on a topographic map, every fifth contour line is darkened. what is this line called? a. key b.slope c.benchmark d. index contour

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments