Atoms, Molecules and Elements
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 noble gases are: helium, neon, argon, krypton, xenon and radon. Properties of Molecules Formed from Atoms in Similar Families
When looking at the properties of molecules formed from atoms in similar families you can compare the similarities and differences. When looking at the periodic table, “Each column within the main-group elements in the periodic table is called a family or group of elements and is designated with a number and a letter printed directly above the column,” (Tro, 2009). Both are bent molecules. Under normal conditions is a gas while is a liquid. Another property of molecules formed from atoms in similar families is the way the electrons are configured in the outermost shell of the individual atoms. Electron Structure of Atoms and Why it is Important
“Once scientist had accepted the idea that electrons were constituents of all matter, theories attempting to explain just how electrons were incorporated in the structure of the atom began to develop. This was especially true after Rutherford had discovered that most of the volume of an atom was occupied by electrons. Both chemists and physicists became interested in the electronic structure of atoms-the chemists because thy wanted to explain valence and bonding, and the physicists because they wanted to explain the spectra of atoms, the light emitted when gaseous atoms were raised to a high temperature or bombarded b electrons,” (Gen Chem Textbook, n.d.). Going back to the valence electrons, these are important to know because then you can predict determine the properties of chemicals and how they may or may not bond with other chemicals.
In conclusion, halogens and alkali metals are extremely reactive whereas noble gases are not because of the valence electrons of those elements. By gaining or losing electrons halogen and alkali metal have a high chemical reactivity and since noble gases are content and have a full valence shell they are inert, meaning they have no chemical...
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
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