ANS:B - 86.6

The percentage of lead in pure galena (lead sulfide) is approximately 86.6%. This means that for every 100 parts of galena, about 86.6 parts are composed of lead. Galena is a naturally occurring mineral form of lead sulfide (PbS). It is the most important ore of lead and is widely distributed geologically. When pure, galena is composed entirely of lead and sulfur atoms. However, in natural deposits, it often contains small amounts of impurities such as silver, zinc, copper, and other elements. The high percentage of lead in galena makes it an economically important mineral for lead extraction. It is typically mined and processed to extract lead metal, which has various industrial applications, including in batteries, ammunition, construction materials, and various other products.