The periodic table has long served as the fundamentals of the chemical sciences, and its development has been the responsibility of a number of thinkers and theorists. The history of the periodic table is extensive; while many scientists maintained concepts and theories that influenced its development, much of the modern periodic table can be traced to the work of Dimitri Ivanovich Mendeleev (Scerri, 2011). Mendeleev organized the elements by their atomic weights in an increasing order; however, this model remained in dispute due to the gaps in knowledge that it uncovered within the chemical world. As all then-know elements did not perfectly aligned, it was theorized that there were numerous undiscovered elements that had to exist within the periodic table.
Mendeleev’s postulated order allowed for the creation of the modern periodic table due to its ease of organization. Anton van den Broek further improved the period table through the use of atomic numbers to direct the, which proved to be a more logical step. As such, this model remains the standard within the scientific world. Due to the design of the table, researchers were able to analyze and determine further properties about the elements. Overall, table is organized into rows and columns of elements with each row called a period and columns are called groups (Zumdahl and Zumdahl, 2007). These groups are part of different families on the table and there are nine different families in total (Zumdahl and Zumdahl, 2007).
Within these families are the transition metals which make up the largest amount of elements on the table (Zumdahl and Zumdahl, 2007). Transition metals have traditional characteristics of metals such as being ductile, malleable, and having the ability to conduct heat and electricity (Zumdahl and Zumdahl, 2007). A unique attribute of transition metals is that their valence electrons are not only found in their outer shell (Zumdahl and Zumdahl, 2007). Traditionally valence electrons are found in the outer shell only (Zumdahl and Zumdahl, 2007). Other chemical properties of transiton metals include: high boiling temperature, high melting point, being very hard, they can be colored, have several oxidation states, low ionization energy, and positive oxidation states (Zumdahl and Zumdahl, 2007).
Unknown element Y is thought to part of the transition metals based on some of these properties such as the melting point being 1495°C, the boiling point being 2900°C, the first ionization energy is 7600 kj/mol, and the physical state of the metal is solid. These characteristics suggest the elements inclusion as a transition metal. Further it is thought that these elements might be part of period 4 or period 5 on the table. The elements in these periods are different and similar to each other. In period 4 the elements are stable and many are very hard as well (Zumdahl and Zumdahl, 2007). This has led to their use in in a number of industrial applications due to their hardness and rigidity (Zumdahl and Zumdahl, 2007). Many of these elements are toxic and others are vital for an organism’s health, showing that a simple change in proton number and vastly alter the properties of these elements (Zumdahl and Zumdahl, 2007). In period 5 many of the elements are unstable and many are also very heavy (Zumdahl and Zumdahl, 2007). Some hold important biological roles and others are used commonly in the jewelry industry because of their appealing physical properties (Zumdahl and Zumdahl, 2007). Many of these elements are used as alloys within industrial settings, as their pure characteristics are incompatible within industrial needs.
In order to determine the placement of unknown element Y, an analysis of the chemical properties within period 4 and 5 will need to be undertaken. The chemical properties of element Y will be compared to the periodic properties in order to pinpoint its exact place within the table.
- Scerri, E.R., 2011. The evolution of the periodic system, Scientific American, [online] Available at: http://www.scientificamerican.com
- Zumdahl, S.S. and Zumdahl, S.A., 2007. Chemistry. 7th ed. Boston:Houghton Mifflin Company.