Atomic and Ionic Radii (Section)
Consider the isoelectronic ions F- and Na+.
(a) Which ion is smaller?
(b) Using Equation 7.1 and assuming that core electrons contribute 1.00 and valence electrons contribute 0.00 to the screening constant, S, calculate Zeff for the 2p electrons in both ions.
(c) Repeat this calculation using Slater’s rules to estimate the screening constant, S.
(d) For isoelectronic ions, how are effective nuclear charge and ionic radius related?
Chapter 5 Textbook Notes 5.1 Hydrogen, oxygen, and water When two or more elements combine to form a compound, an entirely new substance results 5.2 Types of chemical bonds A chemical bond is the force that holds atoms together in a compound Chemical bonds form because they lower the potential energy of the charged particles that compose atoms Ionic bond – the bond that forms between a metal and a nonmetal; electrons are transferred from the metal to the nonmetal o The metal atom becomes a cation and the nonmetal becomes an anion o An ionic compound is formed with a lattice structure of alternating cations and anions Covalent bond – the bond that forms between two or more nonmetals o Electrons are shared between the atoms o A molecular compound is formed 5.3 Representing compounds: chemical formulas and molecular models Chemical formula – indicates the elements present in a compound and the relative number of atoms or ions of each o Normally list the more metallic (or more positively charged) element first, followed by the less metallic (or more negatively charged) element; cation then anion There are three types of chemical formulas: empirical, molecular, and structural Empirical formula – gives the relative number of atoms of each element in a compound Molecular formula – gives the actual number of atoms of each element in a molecule or compound Struc