Agroup of elements are highly inactive and are used by chemists because of their chemical stability. most are found in pure form. they never bond with other atoms because their outermost electron orbital is full. in which element family are these elements found? a) alkali metals b) alkaline earth metals c) halogens d) noble gases

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.