Why are all of the substances on the periodic table classified as elements? a. substances on the periodic table cannot be dissolved in water or other liquids. b. all elements are pure substances. c. substances on the periodic table cannot be broken down into other substances and are therefore elements. d. substances on the periodic table can be combined to form compounds and are therefore elements.

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?