INTRODUCTION TO UNDERSTAND THE GROUP OF ELEMENTS

Element is the basic unit of all types of matter. At present 114 elements are known. As new elements are adding up, scientists found a systematic way to organise the elements by classifying the elements into groups and periods. 

Below are listed the groups of elements of the periodic table-

Group 1 – Alkali metals.

Group2 – Alkaline earth metals.

Group 3-12 – Transition metals

Group 13-16 – Post transition metals

Group 17 – Halogens

Group 18 – Noble Gases 

The long –form of the periodic table of elements is most convenient and widely used. The horizontal rows are referred to as periods and vertical columns are referred to as groups. Elements which have similar outer electronic configurations in their atoms are arranged in vertical columns called groups. 

There are seven periods. The first period consists of two elements. The subsequent periods consist of 8,8, 18, 18, and 32 elements, respectively.  

The atomic size of an element increases as we go down the group in the periodic table.

ELECTRONIC CONFIGURATION OF ELEMENTS –

The distribution of electrons into orbitals of an atom is called electronic configuration. There is a direct connection between the long form of the periodic table and the electronic configuration of elements.

1. Electronic configuration in periods –

The period denotes the value of n for the outermost or valence shell. The number of elements in each period is twice the number of atomic orbitals available in the energy level that is being filled. The first period (n=1) starts with the filling of the lowest level (1s) and therefore has two elements – hydrogen (1s¹) and helium (1s²) when the first shell (K) is completed. The second period (n=2) starts with lithium and the third electron enters the 2s orbital. Likewise, you can continue with the third period, fourth period, and so on.     

  2.Electronic configuration group wise-

Elements within the same vertical column or group have similar valence shell electronic configurations, an equivalent number of electrons within the outer orbitals, and similar properties. Group 1 elements (alkali metals) all have ns1 valence shell electronic configuration. 

 Talking about the group 13 elements and group 14 elements with their electronic configuration-

GROUP 13 ELEMENTS – BORON FAMILY

Boron is a non-metal while aluminium is a metal. Aluminium shows many chemical similarities to boron. Gallium, indium, thallium, and Nihonium are metallic.

Boron is a rare element that occurs as Orthoboric acid (H3BO3)  and Kernite ( Na2B4O7.4H2O). Boron is found in two isotopic forms 10B (19%) and 11B (81%). Aluminium is the most abundant metal. It is the third most abundant element on Earth’s crust (8.3% by mass) after oxygen (45.5%) and Silicon (27.7%). 

The important minerals of Aluminium are Bauxite Al2O3.2H2O and Cryolite Na3AlF6. In India, it is found as Mica in Madhya Pradesh, Karnataka, Jammu, and Orissa. Gallium, Indium, and Thallium are less abundant elements in nature. Nihonium (Nh) has atomic number 113 and atomic mass 286 g mol-1. Its electronic configuration is 5f146d107s27p2. Nihonium is a radioactive element that is prepared synthetically.

ELECTRONIC CONFIGURATION OF GROUP 13 ELEMENTS-

The electronic configuration of elements is ns2np1. Looking at the electronic configuration, we see that Boron and Aluminium have a noble gas core, Gallium and Indium have noble gas plus 10 d-electrons, and thallium has noble gas plus 14 f- electrons plus 10 d-electron cores. It can be inferred from this that the electronic structures of these elements are more complex as compared to the first two groups of elements. Hence, the difference in electronic structures affects the other properties and consequently the chemistry of all the elements of this group.

GROUP-14 ELEMENTS: THE CARBON FAMILY-

The members of group-14 are carbon, silicon, germanium, tin, lead, and flerovium. Carbon is the seventeenth most abundant element by mass within the earth’s crust. In elemental form, it is available as coal, graphite, and diamond. In a combined state it is present as metal carbonates, hydrocarbons, and carbon-di-oxide gas in the air.

 Carbon is the most versatile element in the world. When carbon is combined with other elements like chlorine, dioxygen, Dihydrogen, and sulphur provides a huge vast array of materials from living tissues to drugs and plastics. Naturally, occurring carbon contains two stable isotopes: 12C and 13C. Third isotope 14C is also present. It is a radioactive isotope and is used for radiocarbon dating. 

Silicon is the second abundant element on the earth’s crust and is present in nature within, in the form of silica and silicates. Silicon is an important component of ceramics, glass, and cement. Germanium exists only in traces. Tin occurs as cassiterite, SnO2 and leas as galena, PbS. Flerovium is a synthetically prepared radioactive element. 

ELECTRONIC CONFIGURATION of Group 14 elements –

The valence shell electronic configuration of those elements is ns²np². 

CONCLUSION-

The modern table arranges the elements in the order of their atomic numbers in seven horizontal rows (periods) and eighteen vertical columns (groups or families). Atomic numbers in a period are consecutive, whereas in a group they increase in a pattern. Elements of the same group have similar valence shell electronic configuration and therefore exhibit similar properties. The four types of elements in the periodic table on the basis of their electronic configuration are s-block, p-block, d-block, and f-block elements.