Bio1332 Biochemistry - Lecture Three - Chemical Bonding

Covalent bonding occurs through the sharing of electrons between two atoms. In this type of bonding, the atoms involved share one or more pairs of electrons in order to achieve a stable electron configuration. This sharing of electrons allows both atoms to fill their outermost energy levels and attain a more stable state.

Valence electrons are the electrons located in the outermost energy level of an atom. These electrons are involved in chemical bonding and determine the reactivity and chemical properties of an element. Core electrons, on the other hand, are the electrons located in the inner energy levels of an atom and are not involved in bonding. Therefore, the correct answer to complete the sentence is "valence," as it accurately describes the type of electrons found outside the core.

If the difference in electronegativity values between two atoms is greater than 1.7, it indicates a large difference in their ability to attract electrons. This suggests that one atom will have a much stronger pull on the shared electrons, resulting in an unequal sharing of electrons and the formation of an ionic bond. Ionic bonds occur between atoms with significantly different electronegativity values, leading to the transfer of electrons from one atom to another to achieve a stable electron configuration.

Ionic bonding involves the formation of ions through the loss or gain of electrons. The two ions are held together by electrostatic forces.

Noble gases do not bond because their outermost energy level, or shell, is completely filled with electrons. Specifically, the s and p orbitals in the outer shell are filled with electrons. This complete electron configuration provides noble gases with a stable and low-energy state, making them highly unreactive and unlikely to form chemical bonds with other elements.