Componentes clave en las reacciones de combustión

What does that mean you dum bum

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).

Hello.the answer is  hydrosphere, geosphere, and biosphere  have a nice day