Group 3 elements, also known as the scandium family. In the order of the transitioning metals, this grouping comes first in the periodical cycle. It is a fairly electropositive group. The elements are often soft metals that tarnish in air. This group consist of scandium, yttrium, and lanthanum and actinium. Several approaches have been taken to understand this Group. Some authors have taken a philosophical view, while others have looked at the natural kinds of the elements. Some authors suggest this Group should be based on chemistry. Some of the elements of this group show covalent chemistry, while others show ionic chemistry. Yttrium, for instance, is strongly basic and exhibits covalent chemistry. Some authors suggest that the element lutetium should be placed in Group 3, replacing the Ca-Y- Hf diagonal sequence. Others suggest that lanthanum should be placed under yttrium (Scerri, 2012).
1. Electronic configuration
General electronic configuration of Group 3 is (n-1) ns2 nd1, while the electronic configuration of its members is as follows (Scerri & Parsons, 2018).
Sc  1s2 2s2 2p6 3s2 3p6 4s2 3d1 or [Ar] 4s2 3d1
Y  1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d1 or [Kr] 5s24d1
La  1s2 2s2 2p6 3s2 3p6 4s23d10 4p6 5s2 4d10 5p6 6s25d1 or [Xe] 6s2 5d1
Ac  1s2 2s2 2p6 3s2 3p64s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 6d1 or [Rn] 7s2 6d1/p>
2. Trend in the physical properties
Elements in Group 3 are soft and ductile, with some metallic qualities. They have low densities, are shiny and have high melting and boiling point. Some of the properties include the atomic radius and the number of protons. The density and electrical conductivity also vary in group (Vernon, 2021).
2.1. Atomic and ionic radii
Atomic and ionic radius of group 3 from Sc to Ac increases with increase in atomic number with the exception of actinium (Vernon, 2021).
Figure 1: Atomic radius of Group 3 elements
Figure 2: Ionic radius of Group 3 elements
2.2. Ionization energy
From top to bottom in group 3 Ionization energy decrease with increase in atomic radius.So scandium has highest ionization energy (Scerri, 2012).
Figure 3: First Ionization Energy of the Group 3 elements
Melting and boiling point of group 3 elements are given below
Figure 4: Melting and Boiling Points of the Group 3 elements
Above values shows that melting point of group 3 elements decreases from top to bottom in group but melting point of actinium is higher than lanthanum. While boiling point of this group elements increases from top to bottom with the exception of actinium (Scerri & Parsons, 2018).
3. Coordination chemistry of Group 3
Elements in Group 3 of the periodic table have different coordination chemistry. These elements are quite electropositive and have less rich coordination chemistry. The elements are relatively simple in structure. In addition to this, they are connected to the rare elements in a very tight way. The elements in this group have an oxidation state of 3+ when examined under a microscope. The coordination chemistry of this group elements is quite different from the other early transition metal groups. Many of the group 3 elements are quite different from the elements in Group 2 because of their different properties. There is a great deal of complexity produced from these distinctions. The majority of these structures have vibrant hues. The reflected light from these complexes appears green (Scerri, 2012).
4.Uses of group 3 elements
Group 3 elements are important in chemistry. Some of the its elements in are used in the production of semiconductors, and some are used in the manufacture of paints, chemicals, and batteries. Some of the uses of Group 3 elements are as metals, semimetals, and rare earth metals. The metals of this group are used for making hard materials and as catalysts. The semimetal metals are used in semiconductor chips, porcelain, and steel. Stronger materials may be created with the help of rarest earth metals when they are included into alloys. Several coordination compounds of this group are used as pigments. They are also useful as catalysts for organic substances. They are also used for pharmaceutical applications. There are many uses for coordination compounds, and they are highly valued as dyes. They are also used in various analytical methods (Scerri & Parsons, 2018; Vernon, 2021).
Among the transition metals, Group 3 elements are the first to appear on the periodic table. These soft metals are associated with the rare earth metals and have covalent and ionic chemistry. In addition, these elements exhibit electrical conductivity and melting and boiling points.
1. Scerri, E. (2012). Mendeleev’s Periodic Table Is Finally Completed and What To Do about Group 3?. Chemistry International–Newsmagazine for IUPAC, 34(4), 28-31.
2. Scerri, E. R., & Parsons, W. (2018). What elements belong in group 3 of the periodic table. Mendeleev to Oganesson: A Multidisciplinary Perspective on the Periodic Table. Oxford University Press, New York, 140-151.
3. Vernon, R. E. (2021). The location and composition of Group 3 of the periodic table. Foundations of Chemistry, 23(2), 155-197.