SpaceHub on Instagram: "Density is the measure of mass per unit volume, showing how tightly matter is packed into a given space, and one of the most striking examples of a high-density substance is the element mercury (Hg). Mercury, atomic number 80, is a silvery liquid metal at room temperature and has a density of about 13.53 g/cm, making it more than 13 times denser than water. This unusual property allows small amounts of mercury to carry significant mass and made it historically useful in d