Ageologist is comparing the properties of different minerals. he rubs each one on a piece of white tile and observes the color of he power that is left behind. what type of test did he perform? color hardness luster streak

What are atoms of the same element with varying number of neutrons

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

How do the kidneys affect homeostasis