armored scale: insect having a firm covering of wax especially in the female
scale insect: small homopterous insect that usually lives and feeds on plants and secretes a protective waxy covering
rutherford atom: first modern concept of atomic structure; all of the positive charge and most of the mass of the atom are contained in a compact nucleus; a number of electrons (equal to the atomic number) occupy the rest of the volume of the atom and neutralize the positive charge