Melissa DuBois
Chem 110
September 16, 2013
Earl Steven Gurley
Atoms, Molecules and Elements
Atoms are the smallest unit of matter and a group of atoms can form chemical bonds in order to form a molecule. Molecules are groups of two or more atoms that have bound together and are the makings of matter. Elements are a substance that has only one type of atom that make up that element. First we can learn about how halogens and alkali metals are extremely reactive, where as noble gases are non reactive. Secondly we have to compare the properties of molecules formed from atoms in similar families versus . Lastly, we can learn about what is meant by the electronic structure of atoms and how knowing the electronic structure of the atoms aid in the prediction of chemical reactions.
Halogens and Alkali Metals compared to Noble gases “In the 1870’s, the Russian chemist Mendeleev developed the periodic table, based upon the relationship between the atomic weights of the elements and their chemical properties,” (Wetzel, 1993). The reason that halogens and alkali metals are extremely reactive while the noble gases are not reactive has to do with the outermost electron shells. Halogens are reactive because they only have seven electrons in their outermost shell and can gain another by reacting with atoms of other elements. A few examples of halogens are: fluorine, chlorine, bromine, iodine, and astatine. On the other hand alkali metals are extremely reactive because instead of gaining another electron like the halogens, alkali metals lose one or two electrons. Some examples of alkali metals are: lithium, sodium, potassium, rubidium, cesium, and francium. The noble gases all have similar properties under standard circumstances. They are all odorless, colorless and a very low ability to react with other chemicals. The noble gases are inert, meaning not reactive, because their outer shell of electrons is full and stable. Some examples of
References: Gen Chem Textbook. (n.d.). The Electronic Structure of Atoms. Retrieved from http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/The-Electronic-Structure-of-Atoms-519.html Tro, N. J. (2009). Introductory chemistry (3rd ed.). Upper Saddle River, NJ: Pearson/Prentice Hall. Wetzel, J. S. (1993). The Periodic Properties of Atoms. Retrieved from http://www.wikipremed.com/home_resources/020200_periodic_properties_concepts.pdf