The groups in the Periodic Table are arranged in columns, which are numbered from left to right. The groups are named according to their reactivity. Certain classes of elements are designated by more descriptive labels than others. Other elements are grouped by similar chemical properties, such as Al and Hg.
There are a total of 18 groups in the Periodic Table, namely:
Group 1: Alkali metals
Group 2: Alkaline-earth metals
Group 3: Scandium Family
Group 4: Titanium Family
Group 5: Vanadium Family
Group 6: Chromium Family
Group 7: Manganese Family
Group 8: Iron Family
Group 9: Cobalt Family
Group 10: Nickel Family
Group 11: Copper Family (Coinage metals)
Group 12: Zinc Family
Group 13: Boron Family (were referred also as triels)
Group 14: Carbon Family (were referred also as tetrels)
Group 15: Pnictogen Family
Group 16: Chalcogen Family
Group 17: Halogen Family
Group 18: Noble Gases Family or Inert Gases Family
1. Types of group
Usually, elements are grouped into one of several types of groups. Each group has a particular number of valence electrons, which help distinguish it from the others. The elements in the atomic table are organized into 18 different categories, called “groups” or “series” and further subdivided into “types A” and B (Kwatra, 2017).
1.1. Subgroup A
s and p block of periodic table constitute sub group A of periodic table. Subgroup A includes group 1 group 2 group 13 group 14 group 15 group 16 group 17 and group 18. You may find another kind of naming of groups such as IA, IIA, IIIA, IVA, VA, VIA, VIIA, VIII, A, but were obsolete. Elements belonging to these classes are referred to as paradigmatic examples.
1.2. Subgroup B
The d block of periodic table constitute sub group B. In subgroup B, there are 10 groups in which group 8 group 9 group 10 are collectively considered as single group. So there are eight groups in subgroup B. In old times, they are written as IB, IIB, IIIB, IVB, VB, VIB, VIIB, VIIIB. They are transition elements.
2. Characteristics of groups in periodic table
Generally, elements within the same group exhibit similar chemical properties. In addition, their electronic configurations are similar. But, in the case of some elements, the physical properties differ. These differences are known as periodic trends. The periodic table shows these trends (Smits, 2020).
2.1. Valence electrons
Valence electrons, also called outer-shell electrons, are negatively charged particles that play a key role in the formation of chemical bonds. They can absorb energy, release energy in the form of photons, and influence the bonding properties of an element. A substance’s bonding capacities are proportional to its valence electron count. It also indicates the stability of the atom. When all of an atom’s valence electrons have a somewhere to go, the atom is steady. The proportion of valence electrons in an atom is denoted by its grouping. In the periodic table, the number of valence electrons increases from left to right as an element moves from the first to the eighth row. This is because the size of an atom decreases from one period to the next. This is because of the Zeff effect. The size of the atom decreases down a group because the valence electrons are located further from the nucleus.
2.2. Size of atom
The size of an atom is largely determined by its number of valence electrons. The atomic size must increase so that a wider variety of valence electrons may fit within. This effect is called the shielding effect. Several different ways to measure atomic size exist. Chemists typically use X-ray methods to determine atomic size. There is a one-to-one relationship between the mass of an atom and the number of protons it contains in its nucleus. This number of protons is known as its nuclear charge. The larger an atom’s radius, the fewer its protons, and vice versa. The reason for this is because electrons gravitate toward strongly attracted protons (Kwatra, 2017).
2.3. Valency
Valency is a term that is used in science to define the capability of atoms to combine with other atoms. valency is also used to define the behavior of molecules and to explain their arrangement in solids. This concept has also been used in the study of biological structures, like proteins. It is also important to understand valency in order to understand chemical reactions (Smits, 2020).
Conclusion
Determining the qualities of different elements is made easier by their arrangement in groups, as seen in the Periodic Table. It’s also useful for pinpointing an element’s atomic numbers and establishing its valence. The table is based on commonly accepted groupings of elements.
References
1. Schwerdtfeger, P., Smits, O. R., & Pyykkö, P. (2020). The periodic table and the physics that drives it. Nature reviews chemistry, 4(7), 359-380.
2. Kwatra, B. (2017). LOCATOR THEORY FOR ELEMENTS IN PERIODIC TABLE ‘LEPT’. Glob. J. Pure Appl. Chem. Res, 5, 9-10.
3. Zou, Z., Fu, L., Song, X., Zhang, Y., & Liu, Z. (2014). Carbide-forming groups IVB-VIB metals: a new territory in the periodic table for CVD growth of graphene. Nano letters, 14(7), 3832-3839.