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).
1 Crystalline solids are three-dimensional analogs of a brick wall. 2  They have a regular structure, in which the particles pack in a repeating pattern from one edge of the solid to the other. 3  Amorphous solids (literally, solids without form) have a random structure, with little if any long-range order.he extent to which a solid is crystalline has important effects on its physical properties. Examples: The polyethylene used to make sandwich bags and garbage packs is an amorphous solid that consists of more or less randomly oriented chains of (-CH 2 -CH 2 -) linkages.