Chemical Periodicity

ABSTRACT

The chemical periodicity was demonstrated by using different samples of Group IA, IIA and IVA elements that was placed on different test tubes. Their characteristics, namely color, appearance, solubility and physical state is keenly observed. Their solubility and pH were tested under 10 mL of distilled water and litmus paper. By doing such, the experiment exhibited the common characteristics of elements that do belong to the same group. It also showed that all elements that belong to Group IA are soluble. Group IIA elements showed solubility too, however, some of its member elements did not submitted to its solvent. MgO and CaO both showed solubility and turned out to be basic. The knowledge of chemical periodicity can help one predict the properties of a known or an unknown elements. Also a balanced equation was written to show the reaction between oxides and water.

INTRODUCTION

Chemical periodicity is defined as the similarities of chemical elements that are close to each other in the periodic table. The periodic table of the chemical elements is a tabular display of elements. The periodic table consists of horizontal rows called periods and vertical columns called group or families. Metals are aligned to the left, Non-metals listed on the right, and the metalloids are in between of the metals and non-metals (the diagonal from Boron to Polonium). The table can be neatly divided according to type of orbital being filled (representative elements, noble gases, transition elements, lanthanides and actinides), each their own distinctive properties. Each group of designated elements can be designated with a name- Group IA as alkali metals, group IIA as alkaline-earth metals, Group IIIA as boron family, Group IVA as carbon family, Group VA as nitrogen family, Group VIA as Chalcogens and Group VIIA as Halogens

MATERIALS AND METHODS

The small amount of elements Li₂CO₃, Na₂CO₃, K₂CO₃, MgCO₃, CaCO₃ and BaCO₃ were placed in different test tubes. After identifying their physical state, color and appearance of each, their solubility was then tested using 10 mL of water.

For the Group IVA Element, each small amount samples of C, Sn, Si, and Pb was placed in different test tubes. Then its physical state, color and appearance were identified. For Group IIA Metal Oxides, a small amount sample of MgO and CaO was placed indifferent test tubes. 10 mL H₂O was added to each samples and it was test through the use of litmus paper. A balanced chemical equation for each sample was written to show the reaction of the oxides and water.

DATA AND RESULTS

Elements in Group IA, Group IIA, and Group IVA and some metal oxides of Group IIA are observed based on their similarities and differences form one another. On the Table 1, 2 and 3 shows the results of the experiment.

On the Table 1, it contains the Group IA and Group IIA elements, by the given elements such as Li₂CO₃, Na₂CO₃, K₂CO₃, MgCO₃, CaCO₃ and BaCO₃, they are being observe by their physical state color and appearance. The Physical state of all given elements are all solid and their color are all the same color white. But these six elements are different from one to another according to the appearances and their solubility in water, this results shows that the similarities of this elements are based on their properties within groups that are due to chemical periodicity which stems from the valence electrons of atoms, while their differences are from the uniqueness of their atomic structure.

On Table 2, some group A elements were observed. All Carbon (C), Sn (Tin), Si (Silicon) and Pb(Lead) are solid, and only their color and appearance varied. According to Chemical Periodicity, metallic properties of the elements decrease from left to rightacross a period and increase from top to bottom within a group. And their similarities are based on thesame number of valence electrons account while their differences are based on their variations in atomicstructure.