CH 115 1st Edition Lecture 8Unit 1: Atoms, Isotopes, and IonsOutline of Last Lecture I. Writing Electron Configurationsa. Expanded, Condensed, and Noble Gas Configurationsb. Atoms vs. IonsOutline of Current Lecture II. Atomic RadiiIII. Ionic RadiiIV. Ionization energy vs Electron AffinityCurrent LectureAtomic Radii- Important Information  Isoelectronic ions– ions with the same electronic structure. Effective Nuclear Charge – the nuclear positive charge experienced by outer electrons- The atomic radius is determined by measuring the distance between two identical nuclei and dividing by 2.- The size of the atomic radius (FOR MAIN GROUP ELEMENTS ONLY) gets bigger as you go right to left on the periodic table. Example: Neon (Ne) is a lot smaller than Lithium (Li).- The size of the atomic radius also gets bigger as you from top to bottom on the periodic table. Example: Helium (He) is a lot smaller than Radon (Rn).- The size of the atomic radius (FOR TRANSITION METALS ONLY) is smallest in the middle and largest on the edge of the periodic table. Example: Zinc (Zn) is a lot bigger than Manganese (Mn).Ionic Radii- Cations are always smaller than the neutral atom - Anions are always larger than theneutral atom- Example: Ni2+ < Ni; O2-> O2These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Within a group of isoelectronic ions, ionic radii decrease with increasing atomic number- Among just cations, ionic radius trends match the atomic radius trends- Among just anions, ionic radius trends match the atomic radius trendsIonization Energy vs Electron Affinity- First ionization energy (IE1) – the energy needed to remove the most weakly boundelectron from a neutral atom in the gas phase - Second ionization energy (IE2) – the energy required to remove the next electron- IE’s are always positive  Removing an electron from the positive charge of the nucleus requires energy - IE2 is always greater than IE1 The effective nuclear charge is greater IE’s for core electrons are much greaterthan those for valence electrons- Electron affinity – the amount of energy absorbed when an electron is added to an atomin the gas phase. Atoms with very negative electron affinities form anions easily.- Noble gases all have positive electron