Theme 3- Quantum Numbers & Orbitals_Students
Page 1: Quantum Numbers and Atomic Orbitals
Quantum Numbers:
Indicate the energy level and shape of atoms.
Values include principal quantum number (n), angular momentum quantum number (l), and magnetic quantum number (m_l).
Atomic Orbitals:
1s, 2s, 2p, 3s, 3p, 3d, as defined by their specific quantum numbers.
1s has no nodes; 2s has one node; 3s has two nodes; 3p and 3d have multiple orientational configurations.
Example orbital configurations:
1s: spherical
2s: one spherical node
2p: three orbitals with different orientations
3p: similar to 2p but with nodes
3d: five orbitals with varied shapes.
Page 2: Outline Topics
Electromagnetic Radiation
Emission Spectrum & Bohr’s Theory of the hydrogen atom
Quantum Numbers
Atomic Orbitals
Page 3: Learning Outcomes
Understand the atomic model of orbitals.
Use the atomic model to allocate quantum numbers to electrons.
Page 4: Key Elements
Barium (Ba): Atomic number 56
Copper (Cu): Atomic number 29
Calcium (Ca): Atomic number 20
Sodium (Na): Atomic number 11
Other elements: Magnesium (Mg) and Strontium (Sr).
Page 5: Types of Electromagnetic Radiation
Radio Waves: Used in broadcasting.
Microwaves: Applied in cooking and radar.
Infrared: Heat transmission from sun and fires.
Visible Light: What is seen; absorbed by objects.
Ultraviolet: Used in fluorescent tubes, harmful to skin.
X-rays: Medical imaging for diagnosis.
Gamma Rays: Kill cancer cells.
Page 6: Electromagnetic Radiation Formula
Energy (E) equation: E = hc/λ
h = Planck's constant (6.626 × 10^-34 J.s)
c = speed of light (2.998 × 10^8 m/s)
λ = wavelength
v = c/λ (frequency in Hz).
Page 7: Photoelectric Effect
Describes light in terms of energy (photons).
Shows energy quantization: E = hv.
Explains the emission of electrons from metal surfaces when exposed to light.
Page 8: Practice Problem for Frequency Calculation
Given: 522 nm wavelength of green light.
Steps:
Use c = λv, rearrange to v = c/λ.
Convert 522 nm to meters: 522 x 10^-9 m.
Calculate v: 5.75 x 10^14 Hz.
Page 9: Emission Spectra
Atoms emit discrete wavelengths, not continuous.
Unique emission spectrum for each element.
Page 10: Line Spectrum Example
Shows emitted light energy corresponding to specific wavelengths (656.3 nm, 486.1 nm, etc.).
Restricted energies relate directly to electron states.
Page 11: Bohr’s Model for Hydrogen
Electrons occupy defined orbits with specific energies.
Energy changes correspond to transitions between energy states.
Ground state: lowest energy level; excited state: higher levels.
Page 12: Practice Problem on Energies
Energy values for hydrogen atom levels:
n=1: -2.179 x 10^-18 J/atom
n=2: -5.448 x 10^-19 J/atom
Page 13: Reflection Time
Pause for individual or group reflection on learning.
Page 14: Quantum Orbitals
Defined as regions holding electrons with varying probabilities.
Maximum of 2 electrons in each orbital.
Page 15: Quantum Numbers Overview
Describe electron location: principal (n), angular (l), and magnetic (m_l).
Page 16: Principal Quantum Number (n)
Size of orbital; integers from 1 to infinity (not zero).
Higher n value = larger orbital.
Ground state (n=1) vs excited state (n>1).
Page 17: Angular Quantum Number (l)
Shapes of orbitals:
l=0 (s), l=1 (p), l=2 (d), l=3 (f).
Values range from 0 to n-1.
Page 18: Magnetic Quantum Number (m_l)
Describes spatial orientation.
Values from -l to +l, defining specific orbital positions.
Page 19: Rules for Quantum Number Combinations
n, l, m_l are integers.
n cannot be 0; allowed: 1, 2, 3...
l: 0 to n-1.
m_l: -l to +l.
Page 20: Practice Problem on Quantum Numbers
Describe combinations for n=3.
Page 21: Reflection Time
Pause for further reflection on quantum concepts.
Page 22: Shells and Subshells
Orbitals share the same principal quantum number (n) form shells.
Subsidiary types are subshells: designated as s, p, d, f.
Page 23: Shells and Subshells Detail
Naming subshells based on l values:
n=1 -> 1s; n=2 -> 2s, 2p; n=3 -> 3s, 3p, 3d.
Page 24: Practice Problems - Orbital Names
Orbital for n=4, l=1? (Answer: A. 4p).
Orbital(s) for n=3?
Page 25: Reflection Time
Final thoughts and reflections on the material learned.
Page 26: Learning Outcomes Restated
Further understanding of atomic orbitals and quantum number allocation.
Page 27: Conclusion
The End!