¿What's the answer to this Periodic Table question?

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.

Type the letter that represents the correct location for each particle type below.

In the particles are arranged in a regular, repeating pattern. a)a crystalline liquid b)a crystalline solid c)all gases d)all solids