Week 1 Atomic Models, Valence Electrons, and Metallic Bonding PDF

9 e  INTRODUCTION TO ATOMIC MODELS AND THE QUANTUM MECHANICAL MODEL  LEARING OBJECTIVES 1 Understand the evolution of atomic models. 2 Explain how the Quantum Mechanical Model describes electron behavior. 3 Appreciate the impact of atomic theory on mod...

9 e  INTRODUCTION TO ATOMIC MODELS AND THE QUANTUM MECHANICAL MODEL  LEARING OBJECTIVES 1 Understand the evolution of atomic models. 2 Explain how the Quantum Mechanical Model describes electron behavior. 3 Appreciate the impact of atomic theory on modern science. Can you determine the parts? 5 1 2 3 4  Can you determine the parts? 1.Atomic number 5 2 3 4  Can you determine the parts? 1.Atomic number 5 2.Symbol 3 4  Can you determine the parts? 1.Atomic number 5 2.Symbol 3.electron configuration 4  Can you determine the parts? 1.Atomic number 5 2.Symbol 3.electron configuration 4.name  Can you determine the parts? 5.Atomic weight 1.Atomic number 2.Symbol 3.electron configuration 4.name ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger THE EVOLUTION OF ATOMIC MODELS SOLID SPHERE MODEL JOHN DALTON British chemist and physicist Proposed the Solid Sphere Model in the early 19th century Indivisible atom ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger THE EVOLUTION OF ATOMIC MODELS PLUM PUDDING MODEL J.J. THOMSON 1856 - 1940 English physicist known for his work on the nature of electrons Proposed the Plum Discovered electrons as Pudding Model in distinct particles the late 19th century From indivisible atom to subatomic particles ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger THE EVOLUTION OF ATOMIC MODELS NUCLEAR MODEL Nucleus discovered Explained the behavior of positively ERNEST RUTHERFORD charged alpha particles in the 1871 - 1937 gold foil New Zealand-born physicist known for his contributions to experiment nuclear physics Introduced the Nuclear Model in the early 20th century ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger THE EVOLUTION OF ATOMIC MODELS PLANETARY MODEL NIELS BOHR 1885 - 1962 Danish physicist known for his pioneering work in atomic structure Proposed the Planetary Model in the early 20th century Explained atomic spectra with precision Introduced the concept of quantized energy levels Bridged classical physics with emerging quantum mechanics ATOMIC THEORY TIMELINE 1803 1897 1911 1913 1920s Solid Sphere Plum Pudding Nuclear Planetary Quantum John J.J. Ernest Niels Erwin Dalton Thomson Rutherford Bohr Schrödinger THE EVOLUTION OF ATOMIC MODELS QUANTUM MODEL ERWIN SCHRÖDINGER 1887 - 1961 Quantum mechanics provides a Austrian physicist renowned comprehensive understanding of for his contributions to electron behavior quantum mechanics Schrödinger's model successfully Proposed the Quantum Model explains multi-electron atoms in the 1920s Quantum mechanics is the foundation of modern atomic theory QUANTUM MECHANICAL MODEL QUANTUM MODEL describes electrons as existing in regions called orbitals Electrons do not have fixed paths; they are found in probability clouds around the nucleus. QUANTUM MECHANICAL MODEL ATOMIC ORBITALS The farther the orbital is from the nucleus, the higher is the energy of the electrons in it. QUANTUM MECHANICAL MODEL ATOMIC ORBITALS 2 electrons 6 electrons 10 electrons The farther the orbital is from the nucleus, the higher is the energy of the electrons in it. QUANTUM MECHANICAL MODEL VALENCE ELECTRONS Electrons in the outermost energy level Number of electrons in the 1 1s subshell Principal quantum number of shell Subshell (n=1) VALENCE ELECTRONS VALENCE ELECTRONS VALENCE ELECTRONS VALENCE ELECTRONS VALENCE ELECTRONS 2 2 6 2 4 1s 2s 2p 3s 3p VALENCE ELECTRONS VALENCE ELECTRONS 2 2 4 1s 2s 2p VALENCE ELECTRONS VALENCE ELECTRONS 2 2 6 2 6 1 1s 2s 2p 3s 3p 4s LEWIS ELECTRON-DOT STRUCTURE Only valence electrons are involved in chemical bonding Element symbol represents the nucleus and inner electrons of the atom. LEWIS ELECTRON-DOT STRUCTURE BOND FORMATION Atoms of elements combine to produce compounds Held together by attractive forces called chemical bonds. Ionic Covalent Metallic CHEMICAL BONDING IONIC BONDING Metal - Nonmetal CHEMICAL BONDING COVALENT BONDING Nonmetal - Nonmetal CHEMICAL BONDING METALLIC BONDING Electron Sea Model + + + + account for the + + + distinctive properties of metals + + + + PROPERTIES OF METALS  PROPERTIES OF METALS High densities High melting points High tensile strength High thermal and electrical conductivities Malleable Lustrous  PROPERTIES OF METALS CONDUCTIVITY The "sea of electrons" is free to flow about the crystal of positive metal ions. These flowing electron can conduct electrical change when an electric field is applied  PROPERTIES OF METALS MALLEABILITY The sea of electrons surrounding the protons acts like a cushion, the overall composition of the structure of the metal is not harmed or changed.  PROPERTIES OF METALS HEAT CAPACITY This is explained by the ability of free electrons to move about the solid. As they move, they efficiently transfer heat (that is, kinetic energy) through the material.  PROPERTIES OF METALS LUSTER The free electrons can absorb photons of light in the "sea," so metals are opaque- looking. However, electrons on the surface can bounce back light at the same frequency that the light hits the surface, therefore the metal appears to be shiny. HOW WOULD OUR WORLD BE DIFFERENT IF SCIENTISTS HAD NOT EXPLORED ATOMIC THEORY? CHECK UP QUIZ 1