Traditional metal working in Mexico more. Important metal working centers include Taxco for silver, Santa Clara del Cobre for copper, Celaya for tin and Zacatecas for wrought iron. Metal working in Mesoamerica, especially of silver, gold and copper was advanced by the time the Spanish arrived, mostly concentrated in the modern states of Michoacán, Oaxaca and Guerrero. The mining and working of metals probably came to Mesoamerican cultures from the south. Metal working was principally in gold, silver, tin and lead, with some copper work known in what is now Michoacán. Gold was generally obtained in powder or pellet form in rivers and streams from
Alkali metal the p-orbitals of the lower shells. Ununennium may also show the +3 oxidation state, which is not seen in any other alkali metal, in addition to the +1 oxidation state that is characteristic of the other alkali metals and is also the main oxidation state of all the known alkali metals: this is because of the destabilisation and expansion of the 7p spinor, causing its outermost electrons to have a lower ionisation energy than what would otherwise be expected. Indeed, many ununennium compounds are expected to have a large covalent character, due to the involvement of the 7p electrons in