Both of them are a hope this helps
Compounds are classified according to the elements that make them up. For example, oxides contain one or more oxygen atoms, hydrides contain one or more hydrogen atoms.
compounds form different types of bonds too. a metal and nonmetal element will create an ionic bond, two nonmetal elements create covalent bonds
Density is a physical property of matter
Answer:
autotrofas estrictas son aquellas bacterias incapaces de crecer usando materia orgánica como fuente de carbono. Mixotrofas son aquellas bacterias con metabolismo energético litotrofo (obtienen energía de compuestos inorgánicos), pero requieren sustancias orgánicas como nutrientes para su metabolismo biosintético.