Near the beginning of the universe, A. the temperature was billions of degrees. B. the density was enormously high. C. the matter could turn into energy and vice versa

Which describes an image that can be produced by a concave lens? the image is real and smaller than the object. the image is virtual and larger than the object. the image is virtual and smaller than the object. the image is real and larger than the object.

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects