Final answer:
The periodic table is organized into periods that correlate with the highest principal quantum number in electron configurations, with different numbers of elements per period based on available orbitals. The d-block includes elements filling d sublevels, and electron configurations inform the chemical and physical properties of elements.
Step-by-step explanation:
The sections of the periodic table relate to electron configurations in a systematic way. There are seven horizontal rows on the periodic table, known as periods, which correspond to the highest energy level of the electron orbitals being filled. Each period has a different number of elements, reflecting the number of orbitals available within that energy level.
Electron configuration gives information about the period an element is in because it indicates the highest principal quantum number of the electrons in an atom. For example, in period 1, the 1s sublevel is being filled, whereas in period 7, the 7s and f sublevels are being filled along with further filling of d and p sublevels for transition metals and post-transition metals respectively. The block of elements with d sublevels being filled is referred to as the d-block or transition metals.
Elements that belong to the same row share a common highest principal quantum number in their electron configurations, and therefore, they exhibit periodic trends in properties like atomic radius, ionization energy, and metallic character. These trends are observed due to the effective nuclear charge and the distance of the valence electrons from the nucleus.