Presentation is loading. Please wait.

Presentation is loading. Please wait.

Lecture 2.0 Bonds Between Atoms Famous Physicists’ Lecture.

Similar presentations


Presentation on theme: "Lecture 2.0 Bonds Between Atoms Famous Physicists’ Lecture."— Presentation transcript:

1 Lecture 2.0 Bonds Between Atoms Famous Physicists’ Lecture

2 Electronic Structure in Atoms Max Planck –Electron (1897) has duality, Wave E=hc/λ = h, –λ =wavelength of electron – =frequency Particle of mass, m e

3 Only specific orbits = Atomic Orbitals –Circumference of orbit = n*λ –for Hydrogen, Z=1, R 1 =0.0529 nm –Z= number of protons Bohr Atom

4

5 Electronic Structure in Atoms Ionization energy = transition from n   Emission Radiation (Light and X-rays) –transition n a  n b gives off Photon with energy Bonding in Molecules – Ionic and Covalent Louis Victor Pierre Raymond duc de Broglie

6 E N Not correct due to charge screening and QM

7 Emission Line Spectra

8 Energy Level Diagrams, Hydrogen 1 K 2 3 4 -13.6 eV -3.40 eV -1.51 eV L -0.85 eV

9 Periodic Table of Element Chemical Properties

10 Heisenberg Uncertainty Principle  (m e v)  x  h/(2π) Cannot specify both momentum (or velocity) and location of an electron at same time Electrons are smeared in space Probability of finding an electron at a location is best way to describe and electron

11 Schrodinger Wave Equation (time independent) Wave Function, ψ=f(r,θ,φ) Probability of finding an electron= | ψ| 2 = ψ* ψi.e. complex conjugate

12 Pauli’s Exclusion Principle - Only one electron in each location accounting for spin Principle Q#Orbital Q#Magnetic Q# Spin Q#

13 Zeeman Effect = Splitting or emission lines if in B field

14 Shape of Orbitals

15 Bonding in Molecules Ionic - electrons stolen Covalent - electrons shared –Metal –hybridization, sp, sp 2, sp 3 Molecular Orbitals for shared electrons = covalent bonds

16 Atoms in Solids Ionic Bonding, NaCl Covalent Bonding Metals Hetero Atoms = Ceramics, e.g. MgO

17 Electrostatic forces in Ionic Solids Many Atoms at various separations –Maudelin Constant, M d –NaCl, a o =0.281 nm and E latttice =8.95 eV.

18 Repulsive Force at small r Total Force = Coulomb Force + Repulsive Force

19 Metallic Bonding Electrons Free to move among all atoms –Electron Gas Determines –Electrical Conduction –Thermal Conduction

20 In Covalent Crystalline Solids, what happens to the atomic orbitals?

21 Molecular Orbitals New Energy –Bonding –Anti Bonding New Shapes to Orbitals if hybridization 1s

22 Bonds Between Molecules Hydrogen Bonding Van der Waals Forces –Dipole-Dipole interactions Dipole Moment = Charge * separation –Permanent –Instantaneous

23 Melting Point Molecular Solids Metals Ionic Solids Covalent Solids Strength of Inter-Molecular Bonds Melting Point

24


Download ppt "Lecture 2.0 Bonds Between Atoms Famous Physicists’ Lecture."

Similar presentations


Ads by Google