An unknown element has chemical behavior similar to that of silicon (si) and lead (pb). the unknown element has a mass greater than that of sulfur (s), but less than that of cadmium (cd). use the periodic table to determine the identity of the unknown element.

The image compares the arrangement of electrons in two different neutral atoms. a figure labeled atom q has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has six black spheres. to the left of this figure is another figure labeled atom p. atom p has a shaded sphere at the center of three concentric circles. the innermost circle has two black spheres. the middle circle has seven black spheres. which of the following best explains the position of the two atoms in the periodic table?