FORMAS EN QUE SE PRESENTA LA MATERIA
https://www.slideshare.net/cvenegaslopez/cmo-se-presenta-la-materia
https://www.slideshare.net/rodrigocaz1/presentacion-ud-materia-presentation
https://www.slideshare.net/profesoraudp/3-clasificacion-delamateria
https://www.slideshare.net/thekillersofquimica/metodos-de-separacion