I need help on the stuff highlighted in the blue

Aluminum–lithium (al-li) alloys have been developed by the aircraft industry to reduce the weight and improve the performance of its aircraft. a commercial aircraft skin material having a density of 2.47 g/cm3 is desired. compute the concentration of li (in wt%) that is required.

In which phase(s) do the molecules take the shape of the container?

Summarize possible ways in which phases of matter could combine to form a solution.