Chem 103 1st Edition Lecture 9Outline of Last Lecture I. Calculationsa. Involving Elementsb. Involving Compoundsc. Mass PercentageII. Periodic Lawa. Periodic TableOutline of Current Lecture I. Bohr TheoryII. Quantum Mechanical ModelIII. ShellsIV. SubshellsV. OrbitalsVI. Electron Structure and LawsVII. Electron Configurationa. Pauli Exclusion Principleb. Hund’s Rulec. Energy Levelsd. Noble Gas AbbreviationThese 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.e. ExceptionsCurrent LectureBohr TheoryTheory of electron behavior in hydrogen atoms. Bohr believed that the electrons moved in a series of circular orbits around the nucleus – these orbits are called shells. Electrons can jump toouter shells by absorbing energy or jump to lower shells by releasing energy. Quantum Mechanical ModelBohr’s theory was partially correct, however, atoms do not stay in a circular orbit because their precise paths cannot be determined. Instead, the atom’s location and energy is estimated to be somewhere around the nucleus. This area is specified with the terms shell, subshell, and orbital.Shells- The closer a shell is to the nucleus, the lower the potential energy while the further an electron is from the nucleus, the higher the energy- Principle Quantum Number (n) – used to communicate where the shell is located (whether it is closer or further from the nucleus)o The value of n can only range from 1 to 7 o Each Period of the Periodic table corresponds with the Principle Quantum NumberSubshells- Every shell is made up of one to four subshells designated by the letter s, p, d, or f- The shell’s n is combined with the subshell letter to communicate where an electron is located- So a p subshell in the third shell (n = 3) is 3pOrbitals- Orbitals are found within the subshell and contain the electrons- Orbitals can hold a maximum of 2 electrons- Each subshell can hold a different amount of orbitalso s subshells consist of a single s orbitalo p subshells consist of three p orbitalso d subshells consist of five d orbitalso f subshells consist of seven f orbitals- The energy of electrons in orbitals increases in the order s, p, d, and f so a 4p electron has more energy than a 5d electronElectron Structure and LawsElements with the same amount of electrons in the outer shells (valence electrons) will behave the same as each other- They are in the same periodic group- They will have similar chemical propertiesElectron ConfigurationGives details of the arrangements of electrons in an atom. Notation is written like this: Pauli Exclusion Principle: - Can only have two electrons in an orbital due to two spin states (up and down)- Electrons have different spin states because they repulse one anotherHund’s Rule: - Electrons will not pair if there are other equivalent vacancies available- Like a movie theatre, individuals will sit in every other seat before they sit next to a stranger)Energy Levels- Because energy levels don’t always depend onn, some subshells will come before others- A tip in how to order subshells in electronconfiguration; follow the arrows - Ex: V = 1s22s22p63p64s23d3Noble Gas Abbreviation- Electron configuration can be written in anabbreviated form- Use the symbol of the closest noble gas to the element (must be in a lower shell)- Ex: Mg = [Ne] 3s2ExceptionsNe: 1s22s22p6Principle Quantum NumberAmount of electrons in subshellSubshell letter- Cr = (normally) [Ar] 4s23d4 ... however, in nature it is [Ar]4s13d5- Cu = (normally) [Ar] 4s23d9 … however, in nature it is [Ar] 4s13d10Below is a chart drawn in class of the first 11 elements on the periodic table in electron configuration. They exemplify several of the Rules and Principles explained above.H 1 1s1He 2 1s2Li 3 1s22s1Be 4 1s22s2B 5 1s22s22p1C 6 1s22s22p2N 7 1s22s22p3O 8 1s22s22p4F 9 1s22s22p5Ne10 1s22s22p6Na 11