The First 100 Years of Quantum Physics Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Molecules Nuclei Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Hydrogen Atom Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The concept of orbits has been replaced by that of wave function orbitals. A complete set of compatible observables: Energy (n) Total angular momentum squared (ℓ) One (any) component of angular momentum (μ) Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms 1 2 Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei H He NB: The circular orbits are only meant to be simplistic depictions of electron wave function “orbitals.” 10 3 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College Li Ne

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The Pauli Exclusion Principle explains the chemical properties of all the elements. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Valence Electron Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei 11 12 Chemistry is the result of vacancies in the outer orbitals of atoms that can be filled with valence electrons from other atoms. Electron Vacancy (hole) Na Mg At this point, things get complicated. The states are filled before the Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The Pauli Exclusion Principle explains the chemical properties of all the elements. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Molecules Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei H H The Hydrogen molecule is formed by covalent bonding. H2 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Molecules Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The Hydrogen molecule at actual nuclei separation of 0.734Å H2 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Molecules Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei NB: Sodium (Na) has a valence of 1. Chlorine (Cl) has a valence of -1. Na Cl Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College Electrically neutral atoms

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Atoms Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The Pauli Exclusion Principle explains the chemical properties of all the elements. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Molecules Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Salt (sodium chloride) is an example of ionic bonding. Na + Cl _ Ionized Sodium and Chlorine Salt Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei The nucleons Charge Mass Lifetime Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei n 1838.7 880 sec neutron p +1 1836.1 > 1031 yrs Nuclei are composed of neutrons and protons proton The electron e -1 1 > 1027 yrs  Charge is given in units of the electron’s charge magnitude. Mass is given in terms of the electron’s mass. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College Lifetime is given as the mean (or average) lifetime.

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei Nuclei Atomic Number Number of protons Atomic Weight Number of nucleons Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Hydrogen p 1 1 Ordinary Hydrogen Each element has many different nuclei, of same atomic number, called isotopes n p 1 2 Deuterium n p 1 3 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College Tritium

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei THE FOUR FUNDAMENTAL FORCES IN NATURE Relative Strength Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Gravity Electromagnetic At higher energies, this classification requires some modification for the weak and strong nuclear forces. Weak Nuclear n p Strong Nuclear Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei Charge Independence Hypothesis: Considering only the strong force, protons and neutrons are identical Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Example: Heavy hydrogen – “deuteron” p n p n Charge independence has its basis in the Standard Model of quarks. Why do the di-proton and di-neutron not exist in nature? The answer lies in the Pauli exclusion principal and a new intrinsic quantized observable. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei Nuclear Spins INDIVIDUAL SPIN TOTAL SPIN Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei S s S s p Two nucleons (Fermions) combined give us a Boson (spin 1 or 0) n Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

is not strong enough to bind nucleons when I = 1! The First 100 Years of Quantum Physics The Quantum Theory of Nuclei Isotopic Spin (isospin) INDIVIDUAL ISOSPIN TOTAL ISOSPIN Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei I i I i p p n p Isotopic spin obeys the same mathematical rules as spin. n n Isotopic spin is an intrinsic observable related to the particle’s electric charge. n p With charge independence, the strong nuclear force is independent of the value of i. The strong force is not strong enough to bind nucleons when I = 1! Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei I i I i Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei p p n n p Isospin can be used to describe heavier nuclei. n p n p He-3 n p n Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College H-3

The Quantum Theory of Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei Isospin mirror Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei Isospin images should have the same energy level structure. 25Mn51 26Fe51 26Fe51 Iron-51 and Manganese-51 are isospin mirror images 25Mn51 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The Quantum Theory of Atoms, Molecules and Nuclei The First 100 Years of Quantum Physics The Quantum Theory of Nuclei 26 25 Lecture 7 The Quantum Theory of Atoms, Molecules and Nuclei The energy levels of these two mirror nuclei match almost exactly. Small differences are due to the much weaker electrical forces between protons. Nuclear energy levels for Iron-51 and Manganese-51 Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Spooky Quantum Goings On Tunneling Entangled States Schrödinger’s Cat Lecture 8 Weird Quantum Goings On Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Tunneling Lecture 8 Weird Quantum Goings On Quantum mechanical tunneling is responsible for many natural phenomena and important technologies. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Tunneling Lecture 8 Weird Quantum Goings On Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Tunneling Examples of Tunneling Lecture 8 Weird Quantum Goings On Scanning tunneling micrograph Tunneling accounts for the basic function of transistors, for some nuclear decays and many other applications. Transistor Alpha decay Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Entanglement Entangled States Lecture 8 Weird Quantum Goings On Total Spin = 0 A B z - axis Entangled states yield probabilities of obtaining the various possibilities upon measurement. A B A B Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Entanglement Entangled States Total Spin = 0 z - axis A B Lecture 8 Weird Quantum Goings On B A - Entangled states introduce the very act of measurement into the interpretation of quantum mechanics. Bob If Alice measures the z component of photon A’s spin and gets →, then she will know for sure that Bob would measure B’s as ←. And vice versa. So what? They were probably that way from the start. But…Alice could just as well have measured the y component of the spin and gotten an exact value. This would violate the uncertainty principle for Sy and Sz. Alice Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Entanglement Lecture 8 Weird Quantum Goings On Schrödinger’s Cat is a famous quantum paradox parable. Cat in a box with a radioactive atom and a bottle of cyanide gas If the atom decays, the emitted alpha particle is detected by a Geiger counter. The electrical signal from the Geiger counter trips a relay. The relay activates a hammer which breaks the glass bottle. The cat perishes. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

Weird Quantum Goings On The First 100 Years of Quantum Physics Quantum Entanglement Lecture 8 Weird Quantum Goings On Before we look in the box, is the cat alive, dead or both? Ψ = χatom(whole)φcat(alive) + χatom(decayed)φcat(dead) The Schrödinger cat fable depends upon the entangled state maintaining its integrity. But for systems for which Planck’s constant is extremely small, this is literally unlikely. Otherwise, we would have much more startling phenomena than an entangled cat state. Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The First Hundred Years The First 100 Years of Quantum Physics The First Hundred Years of Quantum Physics Next Term: The Quantum Physics of Conductors Semiconductors and Integrated Circuits White Dwarfs and Neutron Stars Bose-Einstein Condensates Relativistic Quantum Electrodynamics Quantum Field Theory Quantum Entanglement and EPR John Bell and Bertelman’s Socks Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College

The First Hundred Years The First 100 Years of Quantum Physics The First Hundred Years of Quantum Physics Next Term: The Quantum Physics of Conductors Semiconductors and Integrated Circuits White Dwarfs and Neutron Stars Bose-Einstein Condensates Relativistic Quantum Electrodynamics Quantum Field Theory Quantum Entanglement and EPR John Bell and Bertelman’s Socks The Emeritus College http://www.emerituscollege.asu.edu rjjacob@asu.edu http://www.public.asu.edu/~rjjacob/courses.html Dr. Richard J. Jacob Professor Emeritus of Physics Arizona State University The Emeritus College