Se requiere preparar una solución de 200 g de sal al 18% ¿que cantidad total se requiere? ​

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).

The state or quality of being humid.a quantity representing the amount of water vapor in the atmosphere or a gas.

It is a ok  i know i have a brain functioning well.