1 / 26

QUANTUM MECHANICAL MODEL OF THE ATOM

QUANTUM MECHANICAL MODEL OF THE ATOM. DEFINITION OF TERMS. QUANTUM – UNIT OF ENERGY ORBITALS – space around a nucleus where the probability of finding an electron is greatest. QUANTUM NUMBERS – set of four numbers used to describe the electron’s energy level in terms of:

jenniec
Télécharger la présentation

QUANTUM MECHANICAL MODEL OF THE ATOM

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. QUANTUM MECHANICAL MODEL OF THE ATOM

  2. DEFINITION OF TERMS • QUANTUM – UNIT OF ENERGY • ORBITALS – space around a nucleus where the probability of finding an electron is greatest. • QUANTUM NUMBERS – set of four numbers used to describe the electron’s energy level in terms of: a. distance from the nucleus b. shape of the orbital c. orientation in space (x, y, z) d. direction of electron spin (clockwise, counter-clockwise)

  3. ENERGY LEVELS OF THE ATOMIC ORBITALS 1. MAIN ENERGY LEVEL (MEL). - represents the average distance of the electrons from the nucleus. - values 1, 2, 3, 4, 5, 6 and 7

  4. Electrons in MEL closer to the nucleus have the lowest energy

  5. 2. SUBLEVELS or SUBSHELLS - define the shapes of the orbitals - has four possible shapes called s, p, d and f EACH SUBLEVEL HAS DIFFERENT NUMBERS OF ORBITALS AND EACH ORBITAL CAN ONLY HAVE A MAXIMUM OF 2 ELECTRONS

  6. s p 1 orbital – 2 electrons 3 orbitals – 6 electrons d f 5 orbitals – 10 electrons 7 orbitals – 14 electrons

  7. SUMMARY OF ENERGY LEVELS, ORBITALS AND ELECTRON RELATIONSHIPS

  8. ELECTRONIC CONFIGURATION - Process of arranging the electrons around the nucleus The problem? The solution!

  9. THE RESULT!!!

  10. RULES GOVERNING ELECTRON CONFIGURATION • AUFBAU PRINCIPLE – electrons enter orbitals of lowest energy first. • PAULI’S EXCLUSION PRINCIPLE – only two electrons can occupy a single orbital. • HUND’S RULE OF MAXIMUM MULTIPLICITY– within the same sublevel, electrons prefer to occupy empty rather than half-filled orbitals.

  11. What is the electron configuration of Oxygen? 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p Oxygen has 8 electrons. Its electron configuration is: 1s 2 2s 2 2p 4 2 + 2 + 4 = 8 electrons

  12. ELECTRON CONFIGURATION OF IONS What is the electron configuration of S 2- ? SOLUTION: 1. Solve for the total number of electrons. e - = p+ - c = 16 – (-2) = 18 2. Use the electron configuration chart 1s2 2s2 2p6 3s2 3p6 3. Check the number of electrons used. 2 + 2 + 6 + 2 + 6 = 18

  13. EXCEPTIONS TO THE RULE 24Cr1s2 2s2 2p6 3s2 3p6 4s2 3d4 1s2 2s2 2p6 3s2 3p6 4s1 3d5 29Cu1s2 2s2 2p6 3s2 3p6 4s2 3d9 1s2 2s2 2p6 3s2 3p6 4s1 3d10 √ √

  14. Electron Population Distribution - Shows how the electrons are distributed among the different orbitals - Based on the electron configuration of the elements

  15. Electron Population Distribution Show the electron population distribution for 15P. P has 15 electrons. Its electron configuration is 1s2 2s2 2p6 3s2 3p3. The electron population distribution for P is: 1s 2s 2p 3s 3p

  16. QUANTUM NUMBERS Set of 4 numbers used to describe the electrons in terms of : Distance from the nucleus Shape of the orbitals Orientation in space Direction of electron spin

  17. PRINCIPAL QUANTUM NUMBER, n • Refers to the main energy levels • Related to the average distance of the electron from the nucleus • Can only have integral values of n = 1, 2, 3, 4 etc.

  18. AZIMUTHAL or SECONDARY QUANTUM NUMBER, l • Defines the shape of the orbital. • Also refers to the energy sublevels

  19. MAGNETIC QUANTUM NUMBER, ml Describes the orientation of the orbitals in space. The range of magnetic quantum numbers defined by the formula ml = 2l + 1 and takes the integer value between –l to +l including 0

  20. SPIN QUANTUM NUMBER, ms - differentiates how two electrons behave under a magnetic field. • Can only have two possible values +½ and -½

  21. Example. What are the possible quantum numbers for the outermost electron of oxygen? SOLUTION: Identify the final orbital occupied by the electron. 1s2 2s22p4 2 2 p4 1 -1, 0, +1 +½ , -½

  22. What are the possible quantum numbers for the outermost electron of chromium? SOLUTION: Identify the final orbital occupied by the electron. 1s2 2s2 2p6 3s2 3p6 4s1 3d5 3 3 d5 2 -2, -1, 0, +1, +2 +½ , -½

  23. For each subshells given below, give the maximum number of orbitals and electrons possible

  24. Electron Population Distribution or Electron Orbital Notation Show the electron population distribution for 15P. P has 15 electrons. Its electron configuration is 1s2 2s2 2p6 3s2 3p3. The electron population distribution for P is: 1s 2s 2p 3s 3p

More Related