Classes of metals Classes of metals Class A metals are metals that form hard acids. Hard acids are acids with relatively ionic bonds. These metals, such as iron, aluminium, titanium, sodium, calcium and the lanthanides, would rather bond with fluorine than iodine. They form stable products with hard bases, which are bases with ionic bonds. They target molecules such as phospholipids, nucleic acids and ATP. Class B metals are metals that form soft acids. Soft acids are acids with relatively covalent bonds. These metals, such as lead, gold, palladium, platinum, mercury and rhodium, would rather bond with iodine than fluorine. They form stable
Metals (album) Metals (album) Metals is the fourth studio album by Canadian singer-songwriter Feist. It was released on September 30, 2011 in Ireland, Austria, Switzerland, Germany, Sweden and Belgium; October 3, 2011 in the United Kingdom; and October 4, 2011 in the United States and Canada. The first single from the album is "How Come You Never Go There", which was released on August 12, 2011. The album was supported by a world tour which started in Amsterdam, Netherlands on October 15, 2011 and finished on October 20, 2012 in Latin America. "Metals" debuted on the US "Billboard" 200 at number 7,