What is an ion? A cation? An anion?

Solution : Gold is a chemical element with symbol Au. It is one of the least reactive chemical elements. Gold often occurs naturally in its elemental (native ) form, i.e in purest form. The consumption of gold produced in the world is about 50% in jewelry, 40% in investments, and 10% in industry. Given, Radius of a gold ( Au ) atom = 1.35 Å (a) Express this distance in nanometers (nm) and in picometers (pm). First let’s see how much is 1Å, 1 nm and 1pm in meters. 1 Å= 10 m.0 -9 1nm = 10 m. 1pm = 10 -12m. The radius of Au in nanometers is : -1 = 1.35×10 × 1nm