Rays of light incident on a lens and parallel to the principal axis of the lens converge a. in back of the lens. b. at the focal point of the lens. c. at the center of curvature of the lens. d. in front of the lens.

(apex) when a cup of water is dropped, as the cup falls, the water in the cup falls out true or false?

The solubility of barium nitrate is 9.02 g/100 g h2o at 20°c. a 15.2 g sample of barium nitrate is added to 200.0 g of water at 20°c. is the solution saturated, unsaturated, or supersaturated? a. unsaturated b. saturated c. supersaturated

Two solids are mixed in a flask and stirred. after a few minutes, the flask becomes cold. which of the following best describes this reaction? a. an exothermic reaction b. a combustion reaction c. an endothermic reaction d. a decomposition reaction