Heavy metals elements and the more reactive of the d-block elements. They have a strong affinity for oxygen and mostly exist as relatively low density silicate minerals. Chalcophile heavy metals are mainly the less reactive d-block elements, and period 4–6 p-block metals and metalloids. They are usually found in (insoluble) sulfide minerals. Being denser than the lithophiles, hence sinking lower into the crust at the time of its solidification, the chalcophiles tend to be less abundant than the lithophiles. On the other hand, gold is a siderophile, or iron-loving element. It does not readily form compounds with either oxygen or sulfur. At
Group 7 element high melting and boiling points. Group 7 contains the two naturally occurring transition metals discovered last: technetium and rhenium. Manganese was discovered much earlier owing to its much larger abundance in nature. Rhenium was discovered when Masataka Ogawa found what he thought was element 43 in thorianite, but this was dismissed; recent studies by H. K. Yoshihara suggest that he discovered rhenium instead, a fact not realized at the time. Walter Noddack, Otto Berg, and Ida Tacke were the first to conclusively identify rhenium; it was thought they discovered element 43 as well, but as the experiment could not be