How many grams of Se are there in 2.14 moles of Se?

When light strikes a plane mirror, images form in locations where light does not actually reach. it only appears to the observer as though the light were coming from this position. what type of image is formed?

How do scientists think that gravity affected the formation of our solar system?

Scientific evidence tells us that the cause of earths four season is the tilt of earth as it revolves around the sun. the student is instructed to illustrate this information in a science notebook. how will the student illiterate winter in the northern hemisphere?