65 900 000 in scientific notation

Anton created a chart listing different types of materials. which best complete the chart? (a)x: copper y: glass(b)x: rubber y: copper(c)x: paper y: silicon(d)x: silicon y: glass

Anybody wanna ? (picture included? )

With the simplified model of the eye, what corrective lens (specified by focal length as measured in air) would be needed to enable a person underwater to focus an infinitely distant object? (be careful-the focal length of a lens underwater is not the same as in air! assume that the corrective lens has a refractive index of 1.62 and that the lens is used in eyeglasses, not goggles, so there is water on both sides of the lens. assume that the eyeglasses are 1.90