Why was the development of cast-iron and steel-frame construction techniques significant to the growth of cities?

One or more substances changing into one or more substances is an example of a

The boiling point of liquids is very high what does it indicate

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation: