In severe cases of poison ivy, poison oak, or poison sumac, it is a good idea to see a doctor. Sometimes large blisters need to be drained and sometimes an oral steroid such as prednisone may be useful. Systemic steroids produce rapid resolution of both the itching and the rash.
Crystalline solids have a highly ordered arrangement of constituent atoms, ions or molecules in a three-dimensional layer or lattice giving rise to distinct geometrical shapes. Thee are two important types of crystalline solids. 1  Ionic solids (represented by sodium chloride).
Because of the repeating geometric structure of the crystal, all the bonds between the particles have equal strength. This means that a crystalline solid will have a distinct melting point, because applying heat will break all the bonds at the same time. Crystalline solids also exhibit anisotropy.