According to the above definition and explanation, the long form of the periodic table is labeled into three units like left, right, and middle sections for learning chemistry or physics in science. The left section in the table has group IA and IIA define the extremely high electropositive character but very low ionization energy and always show the positive oxidation number. The right portion contains groups IIIA, IVA, VA, VIA, VIIA with high electron affinity, and non-reactive noble gases like helium, neon, argon, krypton, xenon, and radon. The organization of the middle portion of the periodic table made the relationship between the left and right sections and contains a list of transition metals or d-block and inner transition or f-block elements.
Periodic table blocks
According to the modern periodic law based on the atomic number and valence shell electron arrangement of elements, the different types of metals and non-metals in chemistry are organized to form s, p, d, and f-block on the periodic table.
The name f-block element in the periodic table is given due to the arrangement of electrons, the valence electron enters into ns-orbital and filled progressively according to the configuration rules. Group-1 (hydrogen, lithium, sodium, potassium, rubidium, cesium, and francium) and group-2 (beryllium, magnesium, calcium, strontium, barium, and radium) belong to these classes with valence shell electron configuration, ns1→2, where n = principle quantum number, or the number of periods.
P-block on the periodic table organizes by progressively filled p-orbital in valence shell electronic structure but helium is an exception with electron arrangement 1s2. Group-3, 4, 5, 6, 7, and noble gases belong to p-block elements. Since the second period of p block elements like boron, carbon, nitrogen, oxygen, fluorine, and argon have filled s-orbitals with valence shell electron configuration, 2s2 2p1→6, where n = number of period.
d-block and f-block elements
The name d-block (transition series) or f-block (inner transition series) on the periodic table is used due to the presence of progressively filled d or f-orbitals in the valence shell electronic structure. The transition or inner transition family forms the ionic chemical bond with metals (s-block) and covalent bond with metals non-metals (p-block). Therefore, 3d-block elements like scandium, titanium, vanadium, chromium, iron, cobalt, nickel, copper, and zinc are placed in the middle of the table between s and p-block with valence shell electronic configuration, 4s0→2 3d1-10. The f-block on the periodic table is divided into two series like 4f or lanthanides and 5f or actinides contain many missing elements discovered or synthesized by the nuclear reaction of radioactive isotopes.