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ABSTRACT
The experiment chemical periodicity shows the properties and reactions belonging to group IA, IIA, and IVA. Proper procedures and observations were done to determine the solubility, physical state, color, and appearance of the compounds namely Li2CO3, Na2CO3, K2CO3, CaCO3, and BaCO3. The results shows that Li2CO3, Na2CO3, K2CO3 were soluble in water, while MgCO3, CaCO3,and BaCO3 were not soluble. All of these compounds were color white, they are in solid form, and their appearance were powder like. The sample from Group IVA Elements ( C, Sn, Si, and Pb) were also in solid form. The color and appearance of Carbon(C) are black, dull and rocklike, tin(Sn) was silver and shiny, silicon(Si) was white and powdery, lead(Pb) was gray and dull and powder like. For the Group IIA Metal Oxides, MgO and CaO were tested of their solubility and reaction to Litmus paper. Both of the compounds were soluble in water and remained blue in reaction to blue litmus paper. The compounds turned to blue in reaction to red litmus paper. This means that the compounds are bases.
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I. INTRODUCTION Periodicity can be defined as to the trends or recurring variations in element, properties with increasing atomic number. Periodicity is caused by regular and predictable variations in element atomic structure (Helminstein 2013). It was Mendeleev who arranged the elements in order of increasing mass. Mendeleev was able to predict where there were 'holes ' in his table, or elements yet to be discovered. The history of periodicity started in the middle of the last century chemists generally understood that chemical elements can be grouped together in separate classes according to obvious similarities or dissimilarities in their properties. Thus, flammable alkali metals (that form stable cations) can be naturally separated from poisonous halogens (that
References: Babaev E.and Hefferlin R. 1996. "The Concepts of Periodicity and Hyper-Periodicity: from Atoms to Molecules" : Concepts in Chemistry: a Contemporary Challenge. (Ed. D.Rouvray). Research Studies Press, London, 1996, pp. 24-81. Figueroa, L. and Samonte.J. Laboratory Manual in General Chemistry. 3rd Edition. 2010. C&E Publishing. Helmenstein A. 2013. Periodicity Definition. About.com Chemistry