Advantages And Disadvantages Of Chemistry

Chemistry is a branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances. It is at once a science and an art. Chemistry explains the world around us and the study of molecular shapes and geometry is necessary for understanding different substances. Molecular Geometry is an essential part of chemical science and it is the three-dimensional arrangement of the atoms that constitute a molecule. It determines several properties of a substance including its reactivity, polarity, phase of matter, color, magnetism, and biological activity [1]. It often uses valence-shell …show more content…
The valence pair of electrons repel each other due to similar negative charges and for the molecule to be stable, its geometry has to be arranged in a manner that electron-electron repulsion is minimized [1]. Hence, VSEPR focuses on observable electron density. The advantages of VSEPR are that it can be used to predict the number of regions of high electron density around a central atom as well as structures of molecules or ions that contain only nonmetals by minimizing the electrostatic repulsion between the regions of high electron density. It can also be used to predict structures of molecules or ions that contain multiple bonds or unpaired electrons. However, VSEPR has its limitations as well as it can’t be used to describe the location or orbitals of electrons and it doesn’t explain the existence of chemical bonds. Table 1.1 summarizes the most stable molecular geometry resulting from interactions between valence electrons and lone pairs of electrons as well as all the possible geometries available for a combination …show more content…
The theory predicts molecular geometry by assuming that localized bond are formed, due to the donation of electrons from respective atoms, between atoms. It is used to describe the formation of covalent bonds as well as explain the electronic structure of molecules. According to Valence Bond theory, a covalent bond is formed between two atoms due to the overlap of half-filled valence atomic orbitals from each atom and maximum overlap leads to the formation of the strongest possible bonds [1]. It assumes that electrons of an atom occupy atomic orbitals and are attracted to the protons (nucleus) of another atom. The use of hybrid atomic orbitals in valence bond theory is an excellent tool to describe local sigma bonds and its simpler nature makes it easier to use by chemists. However, despite its easy applications, the valence bond theory is unable to explain the shape and geometry of different molecules. Table 1.2 presents orbital hybridization or the mixing of atomic orbitals into new hybrid orbitals