1. Gold, which has a density of 19.32 g/cm3, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber.
(a) If a sample of gold with a mass of 2.477g, is pressed into a leaf of 4.116 ?m thickness, what is the area (in m2) of the leaf?
(b) If, instead, the gold is drawn out into a cylindrical fiber of radius 2.100 ?m, what is the length (in m) of the fiber?
2. One molecule of water (H2O) contains two atoms of hydrogen and one atom of oxygen. A hydrogen atom has a mass of 1.0 u and an atom of oxygen has a mass of 16 u, approximately.
(b) How many molecules of water are in the world's oceans, which have an estimated total mass of 1.4 × 10^21 kg?